List of nuisances I found. Beware wall of text ahead.

[Sad Teammate]

First of all it's not a review, more like a compilation of complains. McOsu is great and does it's job pretty good however through thousand of hours of playing it I stumbled upon many inconveniences and annoyances. (I played using mcengine.exe, just to stay off radar for my steam-friends :/, so it didn't count hours, but it's like 10+ hours every week since spring of 2018.)

Second of all, forgive my english as I'm not a native speaker. And I don't know anything about coding, so I know nothing about how things work, thus my complains may be cringe or straight up stupid. Sorry for that.
My osu! in-game nickname is pumbossable (for anyone who wants to check), my peak rank was around 300-400 (though long time ago), so I'm pretty confident in my skills and my undertanding of the game.

Long story short I "quit" osu! in 2018 for many reasons, main of which were getting tired of competing with others and constantly trying to chase the meta. But I still liked the gameplay part so I occasionally booted osu! offline.
Then I moved to McOsu completely as I already played offline and gameplay part here is much smoother and richer than in osu!

I understand that some functions are really hard to implement and the game is basically free so I don't demand anything, just stating inconveniences that I noticed. In no particular order, just as they came up in my head.

First things first, replays. They are critical for analyzing mistakes and their absence really hurts. I know that adding them would be a pain in the butt, but just saying that it sucks to boot up osu! just to get one specific play in one specific setup (and still it would not be correct as I use wasapi (great thing btw, love it) and osu! can't run smoothly in 1k+ fps on my current pc, while McOsu can). So, yeah, it sucks.
Moreover, recently i discovered 'Rewind' - super useful program for watching replays. I dream of having it built-in in McOsu, but I understand that it's just a dream. Nonetheless, I would be able to use it if McOsu could atleast export replays. Please?

Secondly, why can't I edit collections in McOsu? It's pretty crucial for practicing and it's really annoying to launch osu! just to change couple of beatmaps.
And while we at it, why changes to local offset don't save after restarting the game? (I didn't really google it, so there can be a problem on my side, sorry if that's the case)
My guess for both of this is McOsu can't change anything in osu!'s folder but I'm not a programmer and don't really know.

Thirdly, any changes in difficulty settings (aside from speed/bpm, I'm talking about changing AR or CS) do not show up on score's plate. Like here: https://i.imgur.com/Ax4x3Xr.png upper is nomod, while lower is CS 7. It's possible to open score and figure out settings there, but you can't tell at the first glance that these two scores are different and that's bad. I mean speed modifier shows up so why not do that for every other changed setting?
Then, experimental mods. If you enable one it would show up as "++" ( https://i.imgur.com/tvQreRS.png ). If you enable two, it would show up as "++++" and so on basically adding two more pluses for every experimental mod enabled. Why? Why not just put mod's abbreviation if it's say less than three and if more then just put one "++" with a pop-up description of all experimental mods used? Current solution looks really weird to me.
And if we are talking about scores, any way to get rid of the scrollbar on the scores' list? I'm talking about this boy: https://i.imgur.com/lauET00.png. It just covers mods and makes things harder to distinct while serving very little purpose.

Then, a minor one, I noticed some kind of a 'bug' with "Use Mods" feature (after right-click on a score plate, allows you to copy mods used in that play): if you make a play with locked AR/OD, "Use Mods" would put settings on where they are in the score (as it should) but would not lock them. But it should imo.

Moving on, there is an option called "Draw stats: BPM". If the bpm in map changes (like in this one: https://i.imgur.com/nMN7dCA.png), this option constanly shows maximum bpm on the map. What's even the point of it then? Why it can't project current BPM of the current moment in real time?
And why the ui only shows min and max bpm but not shows the general one like osu! does? Without it I have to manually remember that this map for example ( https://i.imgur.com/GHaETYv.png ) has 175 bpm, and not at all what McOsu shows.

About support for map's hitsounds. They don't required for practice, thus don't really "need" to be in McOsu but some maps have really good ones and since I don't play osu! I kinda miss them. I don't think it's THAT hard to add support for custom hitsounds since in McOsu you already have beatmap's combo colours and volume of hitsounds, so absence of hitsounds themselves looks weird to me.

In osu! there is a slider that can hide beatmaps below or above certain difficuly, like 'show beatmaps from 0 stars to 10 stars'. Why it's not a thing in McOsu? Filters out a lot of stuff that you won't ever play.

That's all, can't remember anything else even though I really tried to remember. Why am I even writing all this? Because most of these problems don't look hard to solve for me so I feel obliged to tell the developer about them in hopes to get a better experience.
So last one, unrelated to everything above: there was a pp rebalance in osu! When should we expect to see it in McOsu? Just curious as rework looks interesting.

[McKay]

(Keep in mind that McOsu is relatively opinionated, and mostly reflects my own way of thinking in regards to whether a feature is deemed important or not.)

Originally posted by Sad Teammate:

First things first, replays. They are critical for analyzing mistakes.

I strongly disagree. Over the years I have observed this very closely, and found that nobody actually learns or gets better by watching their own replays.
The only real purposes replays serve is to show off to other people, make youtube videos, and for score submission (to be able to detect cheaters and verify the legitimacy of a score in the future).

Originally posted by Sad Teammate:

I would be able to use it if McOsu could atleast export replays.

If I could go back in time, then McOsu would have been written with replay support in mind from the beginning.
But unfortunately this is not the case, and implementing them properly is way too much work now (for me, at the moment, because I do this as a hobby in my very limited free time).

Originally posted by Sad Teammate:

Secondly, why can't I edit collections in McOsu?

If you follow the Discord[discord.gg], or the GitHub repository[github.com], then you would have seen that I'm already working on that, and that it will be included in the upcoming update.

Originally posted by Sad Teammate:

Thirdly, any changes in difficulty settings do not show up on score's plate.
Then, experimental mods. If you enable one it would show up as "++".

Sure, I can see how it would be annoying to have to open the score to check for those details. I've put it on the todo list.

Originally posted by Sad Teammate:

Any way to get rid of the scrollbar on the scores' list?

I'll make it small enough as to where it doesn't overlap. This has been a point at the bottom of my todo list for quite some time.

Originally posted by Sad Teammate:

If you make a play with locked AR/OD, "Use Mods" would put settings on where they are in the score (as it should) but would not lock them.

I disagree, the locking feature is an optional independent operation that should be done manually if desired on top of the current settings.
If you "Use Mods" of a specific score, then those mod settings only match that score as long as you don't change any mods or switch beatmaps, which is what the feature is intended for (i.e. "I want to try getting a better score on the exact same beatmap with the exact same mods").
(Scores don't store whether AR/OD were locked or not, they just store the final AR/OD value.)

Originally posted by Sad Teammate:

Why it can't project current BPM of the current moment in real time?

Beatmaps don't store BPM. BPM is derived from slider velocity, and slider velocity is defined by timingpoints. Slider velocity will change "randomly" throughout most beatmaps many times (like 20+ times, some beatmaps even change it for every single slider), therefore showing the "current" BPM is meaningless/confusing/useless/impractical.

Originally posted by Sad Teammate:

And why the ui only shows min and max bpm but not shows the general one like osu! does?

I agree, adding the average BPM value calculation and using that for both the "Draw Stats: BPM" as well as in the Songbrowser is good. I've put it on the todo list.

Originally posted by Sad Teammate:

I don't think it's THAT hard to add support for custom hitsounds

Please don't assume programming implementation complexity without insight into what is actually required.
My opinion is that beatmap hitsounds and custom sample sets are unnecessary for a practice client (and I personally don't use them in osu! either), so don't expect me to implement them.
As McOsu is open-source, everyone can feel free to write the code themselves and make a PR on GitHub.

Originally posted by Sad Teammate:

In osu! there is a slider that can hide beatmaps below or above certain difficuly, like 'show beatmaps from 0 stars to 10 stars'. Why it's not a thing in McOsu?

Because then people will accidentally change this slider and complain that all of their beatmaps are suddenly missing. I always found this setting stupid. There are a million ways to sort/group/search for beatmaps in the songbrowser. If you are never going to play a specific beatmap, then just delete it.

Originally posted by Sad Teammate:

Why am I even writing all this? Because most of these problems don't look hard to solve for me so I feel obliged to tell the developer about them in hopes to get a better experience.

Thank you for the list, I really like this style of feedback, as it is very efficient.
(As mentioned, please don't assume something "doesn't look hard to solve", it comes across as condescending to developers.)

Originally posted by Sad Teammate:

So last one, unrelated to everything above: there was a pp rebalance in osu! When should we expect to see it in McOsu? Just curious as rework looks interesting.

On discord I said until at least end of december (because that's when I'm on vacation, so hopefully enough free time.)
The pp "rebalance" is actually a fully blown star calc + pp algorithm rework with over 10 PRs and hundreds of lines of code changed.
I have to rewrite the entire star calc code to be structured more similarly to osu!lazer's C# implementation (McOsu is C++, but making it as similar as possible), because otherwise I'm going to lose my mind trying to keep up.

[Sad Teammate]

Thank you for reading it whole and composing an answer. I don't want to make this a q&a session so I'll try to keep it short.
I'm not a part of discord channel nor do I check github, sorry for this, I should have done it before writing those questions.

Now, where were we...

Originally posted by McKay:

I strongly disagree. Over the years I have observed this very closely, and found that nobody actually learns or gets better by watching their own replays.

Have to say that I disagree with this either. It may be a personal preference but during cut streams or high bpm (280+) jumps it's pretty hard to figure out on the go why exactly you missed that pesky note. This is where replays come in handy to understand if you misaimed, fell of the rhythm, going too fast or too slow, etc.

But yeah I understand that it's a hard work and would require a lot of time so... understandable. Sad but nothing practical can be done about it.

Originally posted by McKay:

Slider velocity will change "randomly" throughout most beatmaps many times (like 20+ times, some beatmaps even change it for every single slider), therefore showing the "current" BPM is meaningless/confusing/useless/impractical.

Yep, I agree on that. What i meant more is like when you play a compilation map with like 10 different songs in it it would be nice to have this "Draw stats: BPM" to show the bpm of the current song on the go. But it sounds impossible so... whatever.

Originally posted by McKay:

Please don't assume programming implementation complexity without insight into what is actually required.

My bad, I apologize.

As I said, I understand that custom hitsounds don't need to be in McOsu but I just say that it would be nice if they were.

Originally posted by McKay:

There are a million ways to sort/group/search for beatmaps in the songbrowser. If you are never going to play a specific beatmap, then just delete it.

Welp, there are a lot of beatmaps that have difficulties from like 2* to 7* and deleting them are not really an option. I would be able to delete certain diffculty, yes, IF I could do it in McOsu. Otherwise it's too much hustle to write off the single map and then look for it in osu!
And I know that it's possible to sort everything in songbrowser, the point is I have to do it manually every single time I boot up the game. It's not really a problem but an inconvenience nonetheless.

Originally posted by McKay:

I have to rewrite the entire star calc code to be structured more similarly to osu!lazer's C# implementation (McOsu is C++, but making it as similar as possible), because otherwise I'm going to lose my mind trying to keep up.

Looks like a lot of trouble. What can I say... Good luck!