Convoy

I had an interesting idea for a game the other day, based on the good old fashioned heist trope. You're riding atop a train in some kind of post-apocalyptic badlands, with gangs of baddies riding up alongside and trying to climb on board and take the train over. You run around on top of the train fighting them off, but you can also upgrade the train and add turrets and traps and so on.

Essentially it'd be an iteration of the standard tower defense formula with a few action/rpg elements. But I really like the possibilities that the setting gives you; the train never stops moving, although the scenery changes and the baddies get stronger, there's a kind of absurdist constancy to it. It'd be fun to play with that in the dialogue of the game too. Why are you on top of a train? Where's the train going? Why does it never seem to get there?

Plus I think as an art direction you could do some really fun things with post-apocalyptic vehicular battles. Deserts, forests, icy tundra. Molemen on motorbikes. Spider robots with rocket launcher legs. I mean, the ideas just write themselves.