How to play early version of UKMD (ULTRAKILL Must Die)

Title says it all.

UPDATE 29.01.2025: HAKITA DID SOMETHING WITH DOWNPATCHING. PLAYERS CAN'T DOWNGRADE ANYTHING LOWER THAN UPDATE 13B. REASON CURRENTLY UNKNOWN. UNDER INVESTIGATION.

Introduction

So, you P-ranked all levels on Brutal? P-ranked it even without taking any damage? Made it to Wave 50 in Cybergrind, but you still want to play this game over and over again or Brutal is too easy/boring for ya? Well, then this guide for you! Welcome! Let's begin without further unnecessary preludes, I've already written enough of them.

Q&A

1. Can I beat the game/P-rank/P% No Damage/Wave 50 Cybergrind with it?

Yes. Although I'm not sure about Cybergrind. I'm not playing it.

2. Which mods are compatible?

There's a section for this below.

3. Which leaderboards will work?

Official for Levels: works but don't displaying difficulty name
Official (Cybergrind): not works
AngryLevelLoader: not works because it fails to post it (reason: invalid difficulty)

4. What happens if I'll insert different number into "prefs set int difficulty <number>"?

Nothing really. But you can play Harmless/Lenient/Brutal with it. Difficulties in this game written in an array. Here is difficulty numbers for every difficulty:

From -∞ to -2147483648: integer underflow, nothing will happen
From -2147483647 to -1: index outside of array, broken difficulty, playable but nothing will be saved (possible to enter on 11b and before)
0: Harmless (Casual Easy in older versions of the game)
1: Lenient (Casual Hard in older versions of the game)
2: Standard
3: Violent
4: Brutal
5: ULTRAKILL Must Die!
From 6 to 2147483647: index outside of array, broken difficulty, playable but nothing will be saved (possible to enter on 11b and before)
From 2147483648 to ∞: integer overflow, nothing will happen
Any other values that isn't int datatype: error, switching to Standard
‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ ‎ 
Total Difficulties: 4294967295

5. Which store versions of the game will this work on?
In theory, will work on every version. Both on the Steam version, and on the GOG version as soon as it comes out. It will work even on a pirated copy of the game.

If you have any more questions, feel free to ask in the comments.

!!! NOTES !!!

1. I'm not responsible for your actions. If you're broke the game - it's only your fault.

2. If you're don't know how to unpack archive or locate your ULTRAKILL installation folder, leave that guide right now. I'm sorry for that, but I seriously met people who don't understand why do they need drivers and install a 32-bit OS on those PCs that need a x64 OS, but they are already actively playing games and you’ve been helping these idiots for literally a week. I’ve already “led you by the hand” enough in the guide itself. This is also the reason why the guide is written so that everything is already said for you, and all you have to do is do it.

3. this is not ultrakill must die!
Show me a person during Patch 11 times who cared.

4. Don't even write to developers that difficulty is broken. Of course it is. Or you're seriously will be write developers that unfinished leaked content that will be released only in 2026-2027 (Hakita said that UKMD will be finished after releasing Finale, that means somewhere in 2026-2027) and main game development will be finished) is broken? Are you out of your mind?

5. Some savegames from new versions of the game is causing compatibility issues on older versions, and I don't know what is causing that, like 15d savegame don't working with version 12b. In that case, there's nothing I can do. Only solution is make a new savefile. Of course, you can patch your savegame, but even me don't know how. If you somehow know how, please contact me and I add savegame patching section in this guide.

6. About patches 12a and later: YOU NEED TO PATCH GAME FILE EVERY UPDATE. EVEN IF THAT'S A LITTLE PATCH. Don't be surprised that it won't work after the update if you haven't patched the files.

7. Note only for MacOS users: This guide will describe methods for running the software via CrossOver. CrossOver is a paid application, but it offers a 2-week trial period. How you choose to obtain the full version of the software - legally or not - already not my problem and responsibility.

Now, if you have read all the notes and taken them into account, we can continue.

Differences between Violent/Brutal and ULTRAKILL Must Die

Patch 16a -16b (ULTRA_REVAMP Update):

No differences from Patch 15. Except for one, little, small, tiny as atom thing. On 7-4, 1000-THR "Earthmover"' Finale Critical Failure timer is now 30 seconds instead of 80. Good-f***ing-luck getting through this with P%\P% No Damage.

Patch 15a-15d (Full Arsenal Update):

Based on Brutal

Hard Damage is decreased from 50% to 33.(3)%.

Generally increased speed of enemies.

Bosses have 50% damage resist (on Brutal it's 30, or 35 percents).
Way faster projectiles.

Virtue rays have a cooldown, but remain much longer.

On Violent Cerberus if they stomp, there will be one wave, on Brutal - two, on UKMD - three.

Gutterman will fire several bullets horizontally in an arc when the shield breaks.

Senrties now have infinite shots until you won't shoot their antenna.

Sisyphean Insurrectionist won't fall into the pit anymore.

Sisyphus Prime does everything at the speed of light (I don't even know if it's possible to pass P-2 on P rank with this, it's literally an inadequate speed.)

UPDATE: That's possible. Huge thanks to Poot Man that proved me that I was wrong in that regard. Only check that remains is No Damage possibility, and that will mean that P% No Damage (and even V% No Damage) will be possible. I think I'll take care of it in several days.

Minotaur have so much HP that fight with him isn't fun anymore (320 HP).

Gameplay Preview:

https://youtu.be/H99E6miOV70

Patch 14a-14d (Violent Night Update):

Based on Violent, but still the same as on patches 13b and before, except Cerberi doesn't rage anymore at all. (exception if one of they own dies.) It's actually making some rooms way easier, like 7-2 room with sanded Gutterman or P-2 Weezer Room, it probably could still have its part to play on P-3, nevermind. I don't think it worth a separate preview just because of one change.

Patch 13b and before:

Based on Violent

Hard damage converted from damage taken is 50%, instead of 35%.

Generic hell energy attacks (Strays/Schisms/Soldiers) are faster.

Strays have a lower cooldown between shots.

Soldiers are completely immune to explosions.

Stalkers don't die when they explode, and they have an animation where they bring the sand barrel back up after slamming it down.

The ferryman's range is much higher, and subsequently, it's attacks are faster.

Sentries shoot faster.

Cerberi, in addition to getting enraged when one of their own dies, will also get enraged when at low health.

Cerberi pulls his devil trigger getting enraged after losing 2 HP (at 90.91% HP or lower)

Drones will now constantly attack and dodge, they still cannot dodge whiplashes.

V2 can now dodge the whiplash in both of their fights

Gabriel 1, in the attack where he grabs two light axes and throws them, the axes now act as
boomerangs, and will seek the player.

Gabriel 1 can now grab a spear and instantly thrust at the player, with barely any warning.

Gabriel 1, when enraged, can now summon a circle of swords that follow the player, and you must dash out of it when the swords start to thrust in your direction.

The Virtue's light beam is unchanged, although the attack has no cooldown anymore, the Virtue will charge another beam as soon as the other one is over.

Gabriel 2's exploding swords are faster and track better.

Gabriel 2 also has the same spinning swords attack as Gabe 1, also in the second phase.

ALL of Flesh Prison's eyes are Maurices.

Thank this guy on Reddit for the full list for the patches 13b and before. I wouldn’t have written half of this myself. Link on the original post with that list: *click*

Gameplay Preview:

https://youtu.be/jm0F4Jv7lHk

( huge thanks to D_Savez for granting permission to use his video! )
---
If you curious how to play on old versions to play UKMD on them:

1. Win + R or open Terminal/Terminal emulator (depends on your OS)
2. steam://open/console
3. download_depot 1229490 1229491 <manifest ID>
4. ???
5. PROFIT! (as soon as you will get notification that depot download complete)
6. Replace all files from downloaded depot folder in your ULTRAKILL installation folder. As convenient variant, just rename your current ULTRAKILL installation folder to something like "ULTRAKILL <patch name>", then create another ULTRAKILL folder and paste all files in that new empty folder.

Note: If game update will be released, your old version in ULTRAKILL folder will be overwritten. Consider making backups.
---
Where to get Manifest IDs and older demo versions that is not 1.05/Native 1.04 for Linux?
https://docs.google.com/spreadsheets/d/1Y63W5nbtNIpaiAAwzebXyh8qO9SwcudyB3F3ciUaL6c/edit?usp=drivesdk

There you go. D_Savez, thanks again for permission.

Sadly, this table isn't updating anymore because D_Savez left the game and community (I guess until Update 16 will be released, you can leave from UK but UK will never leave from you), if you need a Manifest IDs for Patches 15c and further, use SteamDB Patches info.

Mods compatibility

PluginConfigurator/Configgy:

Works fine. What else did you expect from them?

AngryLevelLoader:

Works fine, but UKMD won't be added to list. To launch levels on UKMD difficulty, you need to start a level, write "prefs set int difficulty 5" in console and restart the level.

JAKET (Join And Kill 'Em Together):

Works fine for all players in the lobby who have patch. Otherwise if player don't have patch he will be sent to Violent/Brutal difficulty.

ULTRATweaker:

It just works...

ULTRAPAIN (can also be used as method to play UKMD from patches 13b-14d, but I didn’t write it in this guide because my method is more universal and suitable for a much larger number of versions.):

As custom difficulty works fine only with patch 13b. If you just need it to play UKMD, then works up to patch 14d. Not works at all on the builds from Prelude Demo 1.00 and 12b (don't know about 13a), and as is already clear from what you just read, from version 15a.

ULTRAPAIN Reloaded:

It actually can play as working method for easy ULTRAKILL Must Die unlock for patches 15a-15d, but I don't think it will last for long. As Hakita wills to rewrite enemy logic in Patch 16, it will be broken again if author won't update it (and I have a feeling that he won't update it, since enemies logic is rewritten from scratch.)

UPD: he actually updated it o_o for ULTRA_REVAMP

Just disable all tweaks and rename ULTRAPAIN in mod settings to ULTRAKILL MUST DIE.

Voila.

Same as previous: can also be used as method to play UKMD from patches 15a-15d, but I didn’t write it in this guide because my method is more universal and suitable for a much larger number of versions.

Hell And Hell:

It just works. Nothing more to add here.

V-Rank Mod by Clearwater:

Just load level on Violent, set UKMD using console and restart it. It won't display V rank as total rank and won't be saved anywhere, but hey, at least you can prove to V-Rank Discord Server that you're V-ranking UKMD.

About V% No Damage - I'm not sure. For example, 2-2 have extremely strict time limit that I'm sure that it isn't possible for V% No Damage, or 5-1.

Banana's Difficulty:

Not compatible. Replacing ULTRAKILL Must Die to Banana's Difficulty everywhere.

UKMDUnlocker by whyis2plus2:[/h1][/u]

Working. Even though, if you install this, you'll get a separator from ULTRAKILL Must Die and Banana's Difficulty. But level progression and ranks still will be shared though.

Maybe there will be more comments about some other mods. If something is wrong with some mod on some version, write in the comments and I will add it to this section.

!!! MAKE BACKUPS !!!

If you don't want to reinstall the game or maybe probably lose your saves, backup your game directory somewhere in the other place on your storage devices.

If you can't make it for some reason, then do everything VERY CAREFULLY.

Now we can proceed.

Patch 12a - Current (16) Patch (Windows)

1. Download dnSpy. Direct link: *click*[github.com]

2. Unzip the archive. If you can’t because you don’t know how to do it, refer to Notes, point 2.

3. Launch dnSpy.exe.

4. Open Assembly-CSharp.dll. This is the file that contains most of game logic. This file is stored in <your ULTRAKILL installation>/ULTRAKILL_Data/Managed. If you don't know where is installed your game, refer to Notes, point 2.

5. Click on the icon with magnifying glass. (or just LCtrl + LShift + K. I don't know which way will be more comfortable for you.)

6. Type in Search Box:

PrefsManager

7. You'll see the search results. Click on it.

8. Then, as soon as you get to it and code of PrefsManager class will open, click there anywhere, and press Ctrl+F. Write there "validation".

9. If you're found "Difficulty validation error", then you are going in the right direction. Now, do you see that "return 4;"? Or "return 3;", if you're patching 12a - 14d versions. I don't know what version you're patching.

10. See that? Good. Now RMB + Edit Method.

Our original code looks like this:

if (num < 0 || num > 4)
{
	PrefsManager.Log.Warning("Difficulty validation error", Array.Empty<Tag>());
	return 4;
}
---
note: there will be numbers 3 instead of 4 if youre patching versions 12a-14d

Now go to the bottom of code and see the line:

base..ctor{}

Delete it including tabs.

Now return to the top of the method and replace 4 to 5. It must look like this.

if (num < 0 || num > 5)
{
	PrefsManager.Log.Warning("Difficulty validation error", Array.Empty<Tag>());
	return 5;
}

Then press Compile.

11. Save all files in File menu. (or LCtrl + LShift + S. I'm again don't know which method will be more comfortable for you.)

12. Now boot the game, go to the level selection screen in some act (not act select screen), open console on F8 (Fn + F8 if you're laptop user) and type "prefs set int difficulty 5".

If console gave you:

> PrefsManager Set difficulty to 5

and then you pressed ESC and difficulty name in menu is ULTRAKILL MUST DIE, then you did everything correct. Congratulations!

If you're already patched the file, start from point 12.

Patch 12a - Current (16) Patch (Linux)

Everything is the same as on Windows.

But dnSpy isn't available for Linux natively (at least compiled, source-code is opened so you can do everything you want with it, maybe even rewrite for Linux) so you have only two ways - rebuild the application from source code or take the less hemorrhoidal route and do it through some kind of compatibility layer.

I'll select PortProton. It has better compatibility because you can use GEProton there.

Here is the link to PortProton: *click*

Note: For example, on Nobara Linux dnsPy don't working right with dropdowns/context menu (make it black) or there might be artifacts on distros like vanilla Fedora KDE or KDE neon.

Note 2: I highly recommend to copy whole "Managed" folder into some place and take Assembly-CSharp.dll from freshly copied folder, then program will find all dependencies by itself and you won't need to add every assembly by yourself.

In case of black dropdowns/context menus open file using LCtrl+O and save it using LCtrl+LShift+S. But "Edit Method" button in that case you'll still have to search and click blindly. Alas.

In case of artifacts... I don't know. There are artifacts, but you don’t need to sit in the program for a long time to edit a couple of lines.

Patch 12a - Current (16) Patch (MacOS)

1. Download, unpack and install CrossOver. *click*[www.codeweavers.com]

2. Press "Install" button, click on Search field and write here game name. Click on "Ultrakill". You can leave the settings the same as Crossover installed automatically, just click the install button again after you click on Steam and wait. If it asks if you want to install any fonts, click yes.

3. Login into Steam and download the game.

4. Download dnSpy (*click*[github.com]) and unpack it.

5. Now click with right mouse button on dnSpy.exe. In context menu - Open With ---> CrossOver.

6. CrossOver will say that this is unlisted application. One of fields will require a bottle to install it. Select bottle when you installed the game.

7. Now, press on Install. It won't fully install, but it will launch. Context menus, except for editor itself won't work though.

8. Press Ctrl+O. Find game installation, then go to ULTRAKILL_Data/Managed/. Select all of .dll's here and open.

9. Press LCtrl + LShift + K.

10. Type in Search Box:

PrefsManager

11. You'll see the search results. Click on it.

12. Then, as soon as you get to it and code of PrefsManager class will open, click there anywhere, and press Ctrl+F. Write there "validation".

13. If you're found "Difficulty validation error", then you are going in the right direction. Now, do you see that "return 4;"? Or "return 3;", if you're patching 12a - 14d versions. I don't know what version you're patching.

14. See that? Good. Now RMB + Edit Method.

Our original code looks like this:

if (num < 0 || num > 4)
{
	PrefsManager.Log.Warning("Difficulty validation error", Array.Empty<Tag>());
	return 4;
}
---
// there will be numbers 3 instead of 4 if youre patching versions 12a-14d

Now go to the bottom of code and see the line:

base..ctor{}

Delete it including tabs.

Now return to the top of the method and replace 4 to 5. It must look like this.

if (num < 0 || num > 5)
{
	PrefsManager.Log.Warning("Difficulty validation error", Array.Empty<Tag>());
	return 5;
}

Then press Compile.

15. LCtrl + LShift + S.

16. Now boot the game, go to the level selection screen in some act (not act select screen), open console on F8 (Fn + F8 if you're laptop user) and type "prefs set int difficulty 5".

If console gave you:

> PrefsManager Set difficulty to 5

and then you pressed ESC and difficulty name in menu is ULTRAKILL MUST DIE, then you did everything correct. Congratulations!

If you're already patched the file, start from point 16.

Patch 12a - Current (16) Patch (ChromeOS)

This was the most pain in the ass thing I've ever done in my life, at least until P-3 comes out and I'll be supposed to P-rank it damageless.

Okay, so the first steps is never usually that hard in the any of other operating systems, so I'll make that *chromeos jumpscare*

Alright, let's start.

BUT before we start with our tasks, you need to completely remove your Crostini container on Ubuntu and create an Arch container, and then enable Vulkan in it. Don’t forget to back up any important data from the container. As for installing the Arch container, you can find instructions on the Arch Wiki or ask ChatGPT for help. This article will cover how to enable Vulkan in the container and install the Steam version from Flatpak. After that, it’s up to you; I won’t explain how to create the Arch container, how to install Flatpak, how to install Steam from Flatpak, or how to create a shortcut in the application menu. This is a guide on launching, not setting up the container, otherwise, the ChromeOS guide would have expanded from 10-15 steps to all 50. Also, if you decide to use this Arch container, you should stick to it, as having both Arch and Ubuntu installed simultaneously causes numerous conflicts. Additionally, it was clearly stated at the beginning of the guide that a basic understanding of how computers work is required. After setting up and installing, come back here.

Did you do it? Well done. Now also difficult part.

Okay, Vulkan is enabled, game is installed, everything is fine... but dnsPy not opening on ChromeOS at all. What to do?

Start a Windows virtual machine. I recommend Windows 10 for it. On the virtual machine, do everything that is needed in "Patch 12a - Patch 15d (Windows)". After successful patching, transfer this .dll file somewhere. You can do it in your Discord, or Google Drive, for example.

Did you transfer the file? Good. Download it on your ChromeOS host machine. And after downloading, ask ChatGPT how to move the patched file from the downloads folder to the desired folder in the game directory via the Crostini terminal.

After replacing you can finally play ULTRAKILL Must Die, but after each update you will have to update .dll on the virtual machine. So if you don't mind wasting space - don't delete your VM.

Patch 11a - Patch 11b (Universal Method)

It's working without any mods and patches.

Open level selection screen (not actually select screen), press F8 to open console and type there "prefs set int difficulty 5". It will work. At that moment there wasn't any fix for that, so play and enjoy.

Patch Prelude Demo 1.00 - Patch 10c (Windows)

NOTE: on some versions (like for example Prelude Demo 1.05) there won't be a final rank screen. That means your ranks and P won't be saved and if you're going NG for that, then you're supposed to use only arms and only blue variations of weapons. Also that means that you're supposed to select next level manually. However, next level still unlocks.

If you're already installed everything, start from point 5.

1. Download BepInEx 5.4.22.0 (x64): *click*[github.com]

2. Download UnityExplorer: *click*[thunderstore.io]

Remember: default button to show/hide UnityExplorer is F7.

3. Unpack BepInEx archive and move all files into your ULTRAKILL installation. Into BepInEx folder, create folder named "plugins" and then unpack UnityExplorer and move all files from unpacked archive into "plugins" folder.

4. Beat first level after tutorial on any difficulty if that's your new save. If no, skip that step.

Note: on some versions of the game any loaded scene will crash UnityExplorer. To prevent this, go to game installation directory and go into BepInEx/config. Open com.sinai.unityexplorer.cfg and find line Hide On Startup. Set false to true and after that you will need to open it manually everytime when you want to activate UKMD.

5. Now, click on Play/Continue (depends on the version) and press Inspector on UnityExplorer menu. Next to red "Close All" button will be drop-and-down menu. Select UI there, point your cursor on difficulty button and press LMB.

6. Select from opened list Standard/Violent/Harmless (NOTE: may be named Casual Easy in some versions)/Lenient (NOTE: may be named Casual Hard in some versions).

7. One more window will open. Find "DifficultySelectButton" here. You should click on it now

8. Do you see

DifficultySelectButton.difficulty

that field? Change it to 5. Click to Apply. Hide UnityExplorer. Press ESC.

9. Finally, click on edited button. Voila. Enjoy.

Patch Prelude Demo 1.00 - Patch 10b (Linux)

Everything is the same as on Windows.

But in order to make it work, you must add into launch options this command:

WINEDLLOVERRIDES="winhttp=n,b" %command%

After that it must work.

Patch Prelude Demo 1.00 - Patch 10b (MacOS)

Pretty much same as Windows, but modloader won't inject itself. Pain in the ass, right?

Alright, here's what you need to do.

If you don't downloaded or running game through CrossOver, do (or repeat) steps 1-3 from MacOS (12a - 15d).

Did it? Good. Now:

4. Return to CrossOver and click on your bottle. In "Bottle Actions", click "Open C: Drive" and navigate when your game is installed.

5. Download BepInEx 5.4.22.0 (x64): *click*[github.com]

6. Download UnityExplorer: *click*[thunderstore.io]

Remember: default button to show/hide UnityExplorer is F7.

7. Unpack BepInEx archive and move all files into your ULTRAKILL installation. Into BepInEx folder, create folder named "plugins" and then unpack UnityExplorer and move all files from unpacked archive into "plugins" folder.

8. Now go back CrossOver and open C: drive again.

9. RMB on empty Space, Get Info. Find "Where" in this menu, and copy path. It will look somehow like this:

/Users/<YOUR USERNAME>/Library/Application Support/CrossOver/Bottles/<YOUR BOTTLE NAME>

10. Now in Dock click Go and click "Go To Folder". Copy your path and click Go.

11. You will get into configs of your bottle. user.reg, click on it, RMB, open with, TextEdit. (although through any text editor, but even TextEdit would be enough.)

12. Find there [Software\\Wine\\DllOverrides].

13. Skip all asterisk-marked DLLs and write after them:

"winhttp"="native,bulitin"

14. Save file.

15. Run game.

You're good to go.

Patch Prelude Demo 1.00 - Patch 10c (ChromeOS)

First step is same as with future versions - make Arch Linux crostini container.

After that, via terminal commands place BepInEx folder and files in ULTRAKILL installation folder and after first launch move UnityExplorer inside of "plugins" folder inside of BepInEx folder.

And write in the launch options same thing as with Linux. After that launch, voila. Just done everything the same as on Windows and edit UnityExplorer configure file to prevent crashes on startup if they will happen.

Finale

I won't waste your time anymore for the finale of this guide, so I'll just say: now you know how to play UKMD before its official release. Have fun.

But if you have read (or at least skipped through all the sections up to this section) and reached here, I want to say - thank you for your attention.

To Do List

> Make ULTRAKILL Must Die imitation for versions even older than Prelude Demo 1.00 for all OS (Windows, Linux, MacOS, ChromeOS)
> Update the guide if methods will be patched

(I'm writing this not only for myself on that case if methods will be patched. Write me in the comments/add to friends and write in DM if that will happen. Thanks in advance.)

[P1N34PPL3]

Yeah I mean I believe it, I was just wondering if there was video proof cause I would have loved to see it

[Poot Man]

you called?

[Pinksun (Cyril) (EN-UK | RU)]

P1N34PPL3, it's possible, he sent me screenshots of this, but screenshots are already lost so source: trust me bro

[P1N34PPL3]

Where can I find the Poot Man proof, man

[Poot Man]

hehe

[T405_MN]

I'm hard. thanks

[Pinksun (Cyril) (EN-UK | RU)]

ehehehehehe

[Lynx]

i committed a war-crime following this guide

[GøthckStar⛧]

Not Bad... Not Bad at All!

[Pinksun (Cyril) (EN-UK | RU)]

thanks... i guess?