Chronotron- Today's Time Waster
Basically you move around the level and carry out a set of actions that should ultimately help you collect the circuit board required to "skip" to the next level. The problem is, those actions won't be enough on their own, so you'll have to warp back in time. When you go back in time, your previous movements are replayed, but you can also move independently of those movements to work in tandem with yourself (or multiples of yourself).
For instance, in the first level there is an elevator that you must use to get to the circuit board. You cannot jump high enough to reach it, and the switch that operates the elevator is too far away from it for you to use it effectively. So, you move your player onto the switch and wait a few seconds, then you move to the time warp. You'll warp back in time to see your first player moving to jump on the switch while you move your "new" player to the elevator to lift you to get the board. Then you can go back to the time warp and move to the next level.
If you you mess up your early actions, you can restart the level. There are 35 levels to keep you busy, and the last 7 are labeled "impossible." We haven't made it that far, but we fear that the amount of time warping that must be necessary in those final levels may cause a black hole.