World of Goo 2 has in-game achievements.

Nice, thank you :)

Reus 2 has in-game achievements, called milestones.

These are the same as the Galaxy achievements, which is currently a problem since the milestones tooltips don't appear unless you have Galaxy running, and without tooltips it's hard to know what the unachieved milestones are (or the achieved ones for that matter). At least on a Mac, the standalone installer still works, you just need to launch Galaxy and quit it before running the game, and as long as the GalaxyCommunication process exists, the tooltips show up. However without Galaxy running, that process seems to terminate itself eventually. Note that the achievements/milestones still unlock without Galaxy, though it's possible they might require an internet connection. Hopefully they fix this Galaxy dependence bug.

Cool, just have to note that the list says "Res 2" instead of "Reus 2".

Ooops - will change that immediately.

Labyrinth of the Demon King has in-game achievements. They are under the in-game pause menu, select left or right until achievements is shown.