I don't know if that'll be the final title, but it'll do for now.
Basically, you control an evil genius villain, sitting in his little control room in his stronghold. Heroes try to defeat you, but you can use your onscreen controls to operate traps, give instructions to minions (I'm thinking the ones you can order around can only build, but they can build automated fighting minions for you), and you can build robots, which you control with a similar method.
It'll all be mouse controlled, with maybe a few exceptions for when the player character is actually using a keyboard. Controlling a powerful robot with the mouse would be hard, but it also explains why video game bosses manage to be so incompetent!
Onscreen controls for when you're sitting in the stronghold would probably be modifiable, to account for new traps and such.
Squidi's
excellent idea had some part in helping this idea come to mind, so thanks to him.
Anyways, this is probably way out of my league, but I'll give it my best shot. Wish me luck!