You know, i kinda like dark souls for its difficulty, and i thinks this game its a bit of that, let me explain what you have to do:
Keep pressed A to keep running, if not you will get outside of the screen and thats a game over
press B once to jump (there is a doble jump)
Press D to crouch and avoid obstacles
Press F to shoot and kill the enemies
But Dont press the key selected that appears at the top of the screen and that changes over time