Epic Astro StoryAfter spending more time with Epic Astro Story (Android), I think it's probably the most interesting Kairosoft game I've ever played, and that's a high bar.
For one, the addition of territory exploration, with your own party of adventurers, is a significant and entertaining addition. Yes, combat is very simple, and the strategic options are limited, but it's still quite fun to send your intrepid band of adventurers into strange lands to explore.
In addition, managing things planet-side is quite complex. In addition to managing your own citizens, you're also trying to attract tourists, make the right products for those tourists to buy, research and develop new technologies, even visit other planets.
In other words, there are a ton of things to do in this game, and more so than other Kairosoft games I've played, it's just not possible to do them all, so the choices are more interesting.
One more note. This is the first time I've preferred playing a KS game on my tablet instead of my phone. I just find it much easier to make selections and see what's going on, because the world is quite busy.
Here's a link to the games page on Android Market, where you can see a ton of screenshots (bright and colorful, like all Kairosoft games).