Ogrezilla
Nerf Herder
I spent like no time playing other people's levels in that game, but I made some pretty sick levels.Access to other people's levels...which is where most of the fun of the game is unless you're one of the few who is naturally gifted at designing levels (I couldn't wait to design my own levels...but I suck at it, so the fun in those games for me is basically having an endless supply of 2D Mario levels).