Not really. Presume that everything is time-reversed, and the game kills you if you do anything not possible when your playback is flipped around and played "forward." Then:
- Obviously, you "emit" dots and fruit and power pellets as you traverse the grid.
- Less obviously, once you populate a dot/fruit/power pellet onto a grid square, you can't visit that position again — as, if reversed, that'd look like you going over those things without collecting them.
- You'd randomly enter the powered-up state, and you'd then have to visit one of the unpopulated power-pellet grid positions in order to emit the power pellet to get out of that state — before the powered-up-state timer expires. (The power-up-state going on longer than that is invalid!)
- While in the powered-up state, you'd see pairs of ghost eyes unavoidably approaching you; they'd touch you, turn into ghosts, and then flee from you. That's fine. But once they become ghosts and move off of the grid-space you occupy, you can't touch them again.
Idea for a "challenge mode" on top of that, since this would probably be too hard for casual play:
A series of levels where you are given a score at the beginning. You must find the path around the map that brings your score exactly to zero, using reverse Pac-Man scoring rules (each dot you lay reduces your score by 10, etc). If you reach zero with more dots to lay, or finish laying down all dots without reaching zero, you die (as those would also be invalid states).
Recording input for these challenge runs would be a cool idea too, as you could have the option to watch the run "forwards" for further entertainment. To lessen the difficulty a little bit, the player could even have access to the "forward" version of a run that completes the desired score target (with appropriate bonuses for players who don't utilize the "hint" run).
