RPG idea, Joker minions

I came up with this idea while trying to fall asleep. I'm not sure if it kept me awake or if I was filling time until I could relax enough to sleep. Anyway, the big idea is that you play as a minion of the DC character The Joker. Not playing the big guy himself but rather playing one of the little people that makes his plan possible.

I see the PCs as something slightly above completely disposable. You'll play the characters that offer skills or abilities that the funny guy wants and can use. So he'll be abusive, mean, and ungrateful to them but wont kill them out of hand... hopefully. In fact the "will he kill you" question could be a mechanic of the game.

So as his minions, you're the one that's got to get the bombs on the other boat, piling the money into a nice burnable pyramid. Maybe you never even follow the big guy onto a heist, those guys are the disposable ones.

I don't see your PCs as able to take on big names, the Batman would shrug them off, the Joker likewise would shrug off any aggression from the PCs. That's not to say the PCs cant do anything, they are completely capable of defeating civilians and cops, they are thug-like henchmen that get things done.

I've no idea what system would work best for this idea, or if it even needs its own system. If you know if this idea's been done, or if you know what system might suit this idea best, please post a comment below.