named something like 'good chance of being solvable' (say >90%),
but doesn't have to mean 'easy'.
Maybe the demo-autopilot should be able to get some wins in about a dozen games...

Some (handpicked) candidates for this category:
Freecell, Double-klondike, Dial,
Maverick, Poker Square (2 Reserves)
the tile-puzzkes, memory- and matrix-games,
Hanoi-Puzzle-4, and a few selected mahjongg-layouts.

Maybe wtih sub-categories like >95% >90% >85% etc..

I think there already was a suggestion for an option 'only generate solvable games',
but cant find it right now, and implementing that would be much harder.