The left and right arrow keys move Pico, the up arrow makes him jump and the down arrow makes him slide (he actually does slide, see for yourself). Use the arrow buttons at the bottom of the screen to change test. If you must attack Gobo, do so by pressing Space nearby him. BTW, with that bouncy plate, there's nothing to see if you use that and jump too high. If there is, tell me and I'll see what I can do.
Added some physics. There are gorges, expressions on Pico when he jumps/falls, cool physics, an annoying Gobo and great art. What else could you want? Update 31/12/2014: Made eyes thicker on falling costume.