I just started playing Trine on Steam this past week, and I'm impressed. The footage of Trine 2 looks pretty great, and I think I'm going to hold out for purchasing the Wii U version if it has a lot of exclusive stuff.
Donkey Kong's Crash Course actually looks as if it would be frustrating.
Arkham City is still in my Steam backlog. I started it some months ago, but the audio was still a little buggy in some of the areas. I had thought to wait a bit to see if some patches or driver updates would help, but for some reason, I haven't felt compelled to go back to it.