Press blocks to open block selection. Choose a block to use for your level. Click to place a block. Clear all clears all your placed blocks. Go lets you play your level. Use arrow keys to move. Checkered flag is finish. Red is obstacle. Stone and grass is ground.
Credit to @Will-Wam for the gravity script Sorry if finish line is glitched! I tried! Oh, poo. Just realized @Yllie made a game just like this. Sounds from minecraft! Update# 1 fixed GO broadcast glitch (basically removed 1 block of code)