Guide since none exist for this game

Spoilers Ahead
Will list Bosses, Powerups, Game Mechanics, Maps, Characters, Secrets, etc

Game Mechanics

- X or Right click to X-Maneuver/Dash
- Z or Left click to shoot.
- In crawler, shooting can be done by holding it down, but will fire significantly faster by spamming the button.
- Double click X/RightClick to use Bomb.
- Shopkeepers appear at the end of level 2 and 4 by default.
- Your score multiplier goes normally up to 4x when killing enemies, fading elsewise except in certain animations.
- Shooting makes you move slower.

Characters

Garret Zappala - Shoots straightforward like a machine gun. Best pilot imo. Overall good stats and feels cleanest to use.

Gwen Rossi - Spreadfire shot machine gun. Increased movement speed in exchange for -1 Max HP. Not really a fan, since higher movement speed can actually make micromovement harder.

John Johnson - Shoots burstfire shotgun-like shots. Higher damage in exchange for being slower. Unlocked by normal game progression.

Sophie Jefferson - Randomized stats. Unlocked by normal progression.

Swagthulu - Best all-around stats, but starts at 1 Max HP. Unlocked for killing the shopkeeper. Has special dialogue in the end and with shopkeepers.

Power-Ups

Coin - Worth 1 coin and 10 points.

Shields Module (S) - Increases your shields by 1. If at NULL HP, will increase back to 1. Any overcapped shields picked up when already at max shields will fill the bar below the shield number. When the bar is full, max shield capacity will increase by 1. Something like 5 shields = 1 capacity.

Red Mushroom - Same as shield.

Health (H) - Increases your max shields by 1 and also gives you 1 shield to fill that new max health slot. Maximum shield capacity is 10.

Fire Power (P) - Increases your damage.

Overload (Lightning) - Lets you overcap your normally 4x score multiplier into 8x score multiplier.

EMP (O) - Obliterates projectiles on screen.

Fire Rate (F) - Increases your Fire Rate obviously.

X Maneuver (Refresh) - Just instantly refreshes your dash.

Speed Upgrade (X) - Increases ship speed.

Missiles(M) - Heavy damage rockets shoot alternating from your left and right. Getting Missiles more than once seems to speed up the rate they shoot at.

Mecha-Turret(Laser) - Blue machine that orbits you and shoots a continuous laser beam.

Mecha-Turret(Missile) - Red machine that orbits you and periodically shoots missiles.

Mecha-Turret(PewPew) - Grey machine that orbits you and shoots whatever your shot is.
-- It seems you can have 3 mecha-turrets at maximum.

Invincibility Star - Makes you invincible for a long period of time. Any enemies you run into will instantly die. The greatest benefit is that if you consecutively ram into many enemies, they will start to drop a significant amount of shield upgrades, one per enemy.

1-Up - Gives you an extra life. You respawn at full HP, however all of your other upgrades are removed, meaning you have to continue using base stats.

Jet Engine - Increases your movement speed by 4. Not a fan of this one.

Scepter of Cthulhu - Adds 2 to your Fire Power

Morphine - Restores shields to full.

Adrenaline - Overcharge and +2 Fire Rate

The Sun - Restores 2 lives and grants 2 max lives.

Flamethrower - Replaces attacks with ones that set enemies hit on Fire

Virus - Attacks poison enemies hit

Holy Grail - Makes your shots rapid-fire with something like +4 fire rate, but -0.2 damage. Shots spread out further, but have a significantly higher amount of projectiles. Do not combine with Plus Ultra or Harpoon, because it will override the firerate and make the projectiles have bad accuracy.

Gattling Gun - Fire Rate +4, Fire power -1.

Laser Beam - Replaces your shots with a continuous laser.

Harpoon - Don't pick this up. Changes your firing into extremely slow-paced high-damage harpoons. Not worth it whatsoever in terms of DPS. If you run this, you have to get it early and then get massive fire rate upgrades.

Plus Ultra - Don't pick this up. Perforating Damage. Fire Power -> Fire Damage. Fire Rate reduced drastically, Fire Damage increased drastically. Seems to basically be harpoon.

♥♥♥♥♥♥ Fire - Don't pick this up unless you have crossbone. Makes your shots rotate around you instead of straightforward.Fire Rate +4, Fire damage +0.5.

Crossbone - Makes your shots shoot up, down, left, and right. Against bosses without hit-collision, can multiply your damage by 4 if you stand on top of them.

Shotgun - Double Barrel Fire. Overrides Crossbone.

EMP Bomb - Obliterates projectiles on screen.

Overload Bomb - Same as overload effect. 8x Score mutiplier

Invincibility Bomb - Same as Invincibility Star.

Crawler Fire Flower - Fire 3 shots instead of 1 when using the crawler. Goes away if you get hit

Tank Module - Massive damage increase. Tanks one hit for you. Hitbox while appearing bigger, is the same as the normal ship. Dashing will launch it forward, giving you invincibility frames but leaving you in the same spot. It can pick up powerups it hits when launched. You get a lot of extra points if you kill the final boss with it intact.

Stages

Stage 1
Earth - Normal Eye enemies. Boss: Mecha Hitler

Debris - Normal Eye enemies. Boss: TGBMA
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Stage 2
Space Texas - Tanky Trains carrying eyes, Star enemies, cowboy eyes that can't hit you if you stand still. Dashable bullets that shoot at enemies. Boss: Gun with Fingerguns

Asteroid Field - Lots of asteroids,eyes, asteroid worms, and lasers. Pipes with Asteroid Worms. Amazing place to pick up many shields. Bosses: Giant Rock Crab Guy

The Sun - Annoying constant left-pulling force. Fire worms, fireballs, eyes, and asteroids. Boss: Meteor Shower Survival

---
Stage 3
Bowling - Lots of dashable objects. Bowling pins and bowling balls. Basically normal eyes. Boss: Ghost from Pacman.

Crawl Level - Significant amount of crawl-spaces. Super good place to get shields. Has tanks on crawl-levels. Boss: Super easy Koopa

Thermal Sun Field - Lots of Suns, Fire worms, and multi-directional shooty skulls. Boss: Edgy Skull
---
Stage 4
Bit Graveyard - Tank Crawler platforms and flamethrowers. Boss: Final Hitler

The First Moon - Eggs that spawn dashable heat-seeking bone hands. Boss: Big Trimorph, Primordial Soup
---
Stage 5
Greenscreen - Boss: Priest Hand Guy

Graph Valley- Boss: Faceless Thing

Gravity Land - Boss: Bill Cipher

Secrets/Tips

- Walled-Off powerups surrounded by asteroid walls can be gotten by waiting for it to shove you against the edge of the screen and you dashing to avoid the damage from it. Alternatively, the Tank Module can be shot into it to obtain the powerup.
- Asteroid Field Green Pipes covered in Brown stuff can be shot and entered. They usually have a red mushroom inside a crawler mini-level.
- You can Loop the game by waiting for the red triangle at the end of stage 5 to leave instead of dashing into it.
- On crawler levels, you can get free Shields by getting many consecutive hits on enemies with a red turtle shell.
- You can do the same by jumping on enemies with the crawler consecutively. Both of these interactions are Mario-references.
- Press Tab to open the Cheat Console. The login Password is ".Login RedDeath". Press Enter to proceed. Type ".Help" to see commands. If you use this, your unlockables will be locked and score won't count.
- The Letters of Doom come randomly in place of Mad Events, in a certain order spelling something out. You have to loop to do them all. Chaos mode is a good way to get these.
- You can shoot the shopkeeper twice to get free ~6 coins. This also extends the time-limit.
- You get a large discount and dialogue for having a shopkeeper on Space Texas.
- Shooting them a 3rd time starts the bossfight. If you win, you unlock Swagthulu pilot.
- To get the 3 million point achievement, play Hardmode and loop. You can have 8x default score multiplier instead of 4x.

Bosses

Refer to Stages for now

- Meteor Shower: Stand slightly elevated from the bottom of the map and keep firing. Only danger is side-meteors and fireballs.

- Zombie Hitler: Keep shooting, weaving between shots and dashing through the waves. One dash will go through two waves. On the second form, just keep shooting, and only dodge of the way if the red arrow indicates he will reach the bottom.

- TGBMA: Stay at the very bottom and spam shots. Very easy boss, only move left and right to weave between shots.

- Giant Rock Crab Guy: Stay in the left-middle and keep firing. His attacks barely reach that spot.

- Koopa: Just stay close by and keep firing. Very low health, so just kill him and run behind him.

- Edgy Skull: In the first phase, weave between the shots normally. In the second phase, move from the top to bottom or bottom to top whenever a dragon spawns. For ease, just dash forward to go from bottom->top. In the third phase, stay at the bottom.

- Final Hitler: Keep spamming shots and weaving shots. Try to stay elevated from the bottom, and jumping if robots get close to you. In the second phase, try to dodge both the wave and the lasers at the same time with one jump if possible when they align.

- Big Trimorph: Basically the same as Primordial Soup, but without spoons. May need to dash through the summons since they are tankier.

- Pacman Ghost: Stand in the middle-right, bait the boss to go through the middle. Go down when it's about to reach the middle-right. Repeat. Can also hit bowling pins into it to speed up damage.

- Fingered Gun: Weave between shots. Hit the bullets on second phase to speed up the fight.

- Primordial Soup: Weave between shots. Try to stay near the bottom so you can hit the incoming skeleton-hands with your shots before they come too close. Hit spoons to speed up process.


- Priest Hand Guy: In the first phase, there is a safe spot in the middle you don't have to move from at all. In the second phase, staying near the bottom is safer. In the third phase, treat it like the Letter of Doom N fight, but in one rotation. Move to the left or right to bait out shots, dash through the wave towards the middle to also avoid the bullets. Fire when possible, repeat very quickly because he gives very little time to shoot.

- Faceless Squid: In the first phase, weave shots normally. Can also dash through the waves. In the second phase, stay at the bottom, and dash forward when the tentacles strike. In the third phase, literally just walk around everything. It moves super slowly. If you need to, dash through them. In the final phase, it's the same as before, but smaller area. Try to stay near the top so you can kite down if necessary.

- Bill Cipher: In the first phase, keep shooting but you will get very little time to do so. Dash forward and then move back down. There will occasionally be a break in the shots that lets you get through a round without needing to dash, so you can keep firing. In the second phase, Just dash forward whenever the fists shoot out near you. In the third phase, it is similar to the second phase, but you want to dash when the second set of fists shoots at you.

- Gloved Red Cyclops Demon Part 1: In the first phase, just weave between shots normally. In the second phase, stay in the diamond between the shots, dashing forward as it reaches the bottom. In the final phase, it's just weaving between shots again.

- Ungloved Skeleton Cyclops Demon Part 2: In the first phase, move down and dash up repeatedly to dodge skeleton hands. Similar in second, but also dodging shots. Third is just dodging shots.

- Cthulhu Part 1: In the first phase, treat it like the blackhole mad event. Stay away from the edges of the map at the start. In the second phase, try to stay to one side so you only have to dodge one side of bullets. In the last phase, weave between shots normally.

- Cthulhu Part 2: Mostly just shooting and weaving. You don't do much damage because of super armor, as it will always end the fight around the same point.

Others

Doom Letters
- Doom Letter G: Stay in the middle and weave in between enemy shots.
- Doom Letter R: Stay in the middle and weave even better in between enemy shots.
- Doom Letter A: Just stay in the middle and dash forward through 2 layers of skulls, holding shoot
and down the whole time. Unless you're playing Gwen, there's almost no chance you get hit.
- Doom Letter N: Go all the way to the left/right to bait the red circles to shooting there. Go to the middle and shoot for awhile until the red circles come back. Repeat.
- Doom Letter D: Stay in the middle and weave shots.
- Doom Letter M: This one is a bit harder, but just weave through the red blood cells and skulls, realizing that the jaw of the skulls is not a hitbox.

- Toilet Alien: Weave shots.
- Red Mushroom Boss: Weave in between shots.
- 1-UP Mushroom Boss: On the first phase, go left and right. On the second phase, it's just platforming. On the third phase, dash to go through 2 waves. You can farm some coins from the eyeball summons too.
- Premonition: Weave in between shots.
- Star Boss: Weave better in between shots.
- Shopkeeper: Weave shots + Like Edgy Skull.

- Grandma-thulu: She has an unholy amount of HP and armor... She has invincibility for the first few rounds. On the first pizza round, staying in the bottom left lets you dodge easily. The gloves can be dodged normally through weaving. The next round of gloves is easy to dodge if you dash through into open areas. The next round of pizza and gloves is easy to dodge in the bottom right area. The dual-lines of gloves is hard to dodge, but you can fit between them pretty easily. The splitting pizza attacks are also hard to dodge, but you can dash when they're about to split, then run back to that area. The pizza spike projectile spam can be dodged by slowly barely dodging and moving from the bottom to the bottom left to the top left.

[Voyager1]

From what I can tell the “tutorial” is basically like an easy-mode run-through of the game...I guess? I beat the five levels of the tutorial, so I’m considering the game “beaten”. Nice guide!