Another game that works very well under Ubuntu on the Surface Pro is Don't Starve. I didn't have much luck with this game under Windows on the Surface, but on Ubuntu I was able to get a good ways into the storyline last night.
If I could come up with a reliable way to throw a right-click event in-game, I think Dungeons of Dredmor would work very well too. Hrm. Maybe I should look at finding an easy way to map the stylus' middle-click as a right click. When I'm doing work or browsing the web, I'd use the stylus as it works out of the box; when I'm playing certain games, I'd remap. Need to look into that. It would open up a lot of options in gameplay. Civilization V under DirectX 9 would be entirely playable that way...