Symbiont

Action-platformer/Shoot-em-up game made for the GBJAM9 in Game Maker Studio 2.

Barely made it before the submission time ended, so I have no idea if you can beat the game properly. Sorry in advance if you can't, but do tell if you managed to defeat the final boss. It's a pretty hard game.

Music didn't make it in, unfortunately. I really did have a couple of jams prepared.

Game graphics made by YoukaiDrawing.

Basic keyboard controls:

Z: B button (shooting, also used for a tentacle attack in platformer mode)

X: A button (jumping, used for charging your shot in shoot-em-up mode)

Arrow keys: D-Pad

Enter: Start button

The game supports XInput gamepads as well.
Keep in mind that it sticks to the Gameboy's control layout, so the A button would be the right button and the B button would be the bottom one.