This Is not a game, it's just a really bad color based platformer physics test. A to float, Up key to jump, Down key to stomp/squish, Left and Right keys to move left/right or to push stuff left/right
Look at the instructions Green - Ceilings Grey/Gray - Walls Black - Floors Blue - Water (reverses and weakens gravity as "buoyancy") P switch from mario and bootleg question mark block along with the brown ladder vine. You're the red thingy.