Legend bonus game?

i was playing God's playing field and i had a great idea for a game. after the legend was released we could make a minigame type thing, with no actual storyline. ugh i can't think of the word. like a branch off of the series, and it would be called The Legend: Kill all humans. it will be kinda like God's playing field and the player will be the aliens and snipe oncoming humans. we could always change the name too! post your ideas here.