I think if you only have one, it might be fun for you to have to throw it to use it, and then go pick it back up, weaving through some trouble on the way.  You’ll also have to be careful where you throw it!

So a mix of realtime with some strategy.

If dodging around to get back your tool is the core concept of the game, the player will require some interesting movement options.  I am thinking WASD to walk, but an ability to sprint, and to leap.  Top-down graphics are the fastest thing I can produce, so I’m going with a control scheme for top-down, looking at the mouse, relative WASD movements.

I am not sure what this tool is, but I think something that can bounce off of walls.  This would give the player two interesting systems to play with.

The problem is that it will also require some enemies, which implies AI.  Maybe not, maybe some more mechanical obstacles would be enough.

I hope to have a guy walking around with WASD before I go to bed – but it’s nearing 2am here in Boston.