Impish Misadventures

I've had this idea for a game for a while, but haven't done anything with it yet, but I thought writing it down would insure I don't forget it.

The high concept would be: "C.S. Lewis's The Screwtape Letters meets GURPS Goblins." It would be an infernal Horatio Alger story (or parody thereof) where young imps try to get ahead in Hell's hierarchy by misadventure, toadying, and blind luck. They would be abused and give out abuse and probably come to comedically horrible ends--only to be respawned in the larvae pools and start their Sisyphean climb to archdevil-hood once again.

The rules would need to be simple, but (like GURPS Goblins) flavorful, and I imagine gameplay as something like (GURPS Goblins) with a bit of Paranoia and D&D with a pinch of Planescape.