The original Cube is also fun, at least as a singleplayer game and comes with a lot of SP maps. The SPMP (or MPSP, i don’t remember :-P) mode also allows playing the MP maps with randomly spawned bots.
The AssaultCube fork adds more realistic environments (relatively to the original game anyway), though it is fully MP oriented. But you can still play with bots.
I’ve been playing System Shock 2, the original version i got from GOG (it took a bit to make the controls work but it works fine, though i found a weird bug with non-Steam games in that if you rename the game it loses the control settings - e.g. i set up the controls when the icon was named “SS2.exe” but when i renamed it to “System Shock 2” later it lost the settings until i renamed it back to “SS2.exe” :-P).
I also played a bit of Stranger of Sword City, a turn-based and grid-based blobber. I find the deck works fine with such games.
Also both games play just fine at ~5Watt settings (i like to optimize the settings per-game to get more battery life out of the system).
You may like the Might and Magic series, be it the earlier tile-based games or the newer free-form games. Check out Matt Chat’s old video on Might and Magic 6 (which is the first free-form M&M and the first in a trilogy, IIRC) where he does some quick intro on how to play the game, stats, etc.