Made in 24 hours (15 hours actually)
HOW TO PLAY
A to move left, D to go right, Space to jump. Use your mouse to aim. Your character automatically fire bullets when airborne.
You can wall-jump by jumping towards a wall, then jumping again. It is also possible to climb on the ceiling, and get down by jumping.
Enemies are immune while white in colour, but that also means that you can touch them without dying. A risky move.