Last week my crappy old Android phone broke, and yesterday I got its replacement, a Samsung Galaxy S2, hooked up and working. The previous phone didn't really have the processing power or battery life to handle games, but this one does, so I'm looking for something I can download to play on breaks at work or other periods of down time. Ideally I'm looking for something with these criteria:
-Free, or at least inexpensive. I don't think phone games tend to be expensive, so I don't imagine this will be a problem. Anything that's in-app-purchase-heavy is probably out, though.
-Reasonably deep, but not too grindy or technical. I want something I can play consistently for a while without getting bored of it, but not something that I'll have to invest time in outside of fifteen minutes once a day or so to enjoy.
-Doesn't require anything peripheral to play well. I'm not going to bother carrying around one of those snap-on gamepads or anything, since at that point I might as well be playing a real console. So something that's satisfactory with just a touchscreen is good.
Anybody have any ideas?