Unfinished. 1 Key for grass, 2 Key for ground eraser, 3 Key for monkey, 4 Key for skull, 5 Key for tree, 6 Key for banana, Click and place. Grass is just grass, eraser deletes grass and trees, monkey is not smart, can drown and will die if not fed in an amount of time, skull deletes monkeys, trees are climbable, and bananas will feed monkeys. (Sorry for the wall of text above.)
Inspired by WorldBox, all graphics, sounds, and code by me.