A tower defense where your enemies constantly observe your strength and make it your weakness. Enemies grow resistant to turret types that kill them, so your task is to keep the board evolving all the time.

If that’s too many words for you, just watch this pretty picture (animated .gif of it in action): http://i.imgur.com/FkZNS.gif

(Of course, I sped up mutation quite a lot just for the sake of this 10-second .gif; things would get pretty hectic if your turrets were eaten at that pace right away.)

You see how there’s no green enemies at the start, but they gradually become more common once the other enemies get killed by green turrets. Green enemies cannot be harmed by green turrets, so the tables get turned, and a smart player will quickly start building red/blue turrets, to which the enemies start growing resistant again…

Well, that’s the basic idea, but it gets more complicated with upgrades, color-specific bonuses, and an electronic wiring system you use to “juggle” active turrets (supposed to be your primary way of interaction and it’s not even shown here).

This one’s not too difficult coding-wise, so hopefully I can focus on the actual game design instead of endless physics/AI bugs.