I really like the Humble Bundles for Android. I already had Carmageddon for android as it was released for free on Google Play the first day it was made available. Of course, it is not nearly as playable as it is on a PC with a real controller, but performance on my Galaxy S2 and Nook HD+ was very good, smoother than it ever ran on my PC back in the day when it first came out.
smaug18: So, are any of these games actually good? I know Carmageddon but I have doubts it's actually very playable on a touch only device.
How is Star Command? That one actually looks fun.
I think the "debut" tag under Star Command and Time Surfer is accurate. They don't seem to be available on Google Play store, at least from what I can see... Punch Quest is highly rated on both Google Play and Amazon App Store. Ravensword seems to get a highly positive response when it works but apparently it is an ambitious game and has had its share of technical issues.