Reduced spawners

Moved invisible walls so that there are 3 "floors" for the balls to bounce on rather than random spots for the balls to bounce on scattered around. Should make the scenario more consistent and have better target distribution rather than them all falling to the bottom eventually.

"Fixed" bug where people could fall on the floor or get stuck on a jump pad. I couldnt actually reproduce these and think they are machine/fps related, so what i did was just put kill tiles on the bottom so the run ends if it happens.