[ars]

> but I would like to see a version with more rules and constraints to follow.

That would actually make it easier, not harder. The more constrains you have the fewer possible options you have, and the easier the puzzle.

[readerrrr]

More constrains does not necessary translate to less choices. And even when it does, less choices do not necessary make it an easier game.

For example: I remove undo move, then you certainly have less choices but, the game is harder( even for a computer ), since you have to remember previous states which were previously accessible via undo.