The game isn't broken; this is just it loading. If you wait for a bit, the game will have loaded, and you can use the full screen button.
i have a couple additions to add if you press "p" you spawn one of those boxes
numpad+ adds to your combonumpad- deals damage
and f1 and f6 start slomo at different speeds
I beat a boss and this happend. (I think I pressed delete after karate man, but I'm not sure.)
edit: just tried it and it didn't work
edit 2: it's pressing backspace
this game was amazing but you kan beat the game by just rotating the yellow block to the characte
maybe you should add a import/export system so people could make a basic starter kit or somthing