This brings to mind an interesting point: perhaps the "real" problem here is the level reset on new blocks.  I suspect we could find a way to allow players to continue working on their current map indefinitely, and submit their "win" if/whenever they do happen to find it.  In this way, bots could quietly mine away "in the background" and would still compete with players (via TargetTime) but wouldn't disrupt those players.  I have a rough idea of how this might be able to work: when you start a map you create a tx announcing your intent to play and your game doesn't start until your tx is mined and then seeds the map with the block in which your tx was mined.  When you submit your PoW it must reference your tx hash to be valid.  The initiation TX could even be given a fixed fee (like Huntercoin) which would help to create demand for the coin. (Since you'd need one to start a game.)  This model would be similar to what has already worked well for HUC I think.

Keep in mind that currently each block you get a *large* set of maps (a full 32 bits of search space!) to choose from for your "level."  Basically, 1MOTO would buy you one nonce's worth of individual maps... however big the nonce is would determine how many maps that is.  A full 32 bits might be too large, but it should be left sufficiently large so you don't end up paying for a set of maps that are all entirely unplayable, etc.  Maybe 8 bits? 256 maps?  (Plus there's something cool and retro about it being 8bit, yah?)  I dunno, that might be too few.... there are some other things to consider.