I'm playing a lot of stuff on my Kindle Fire, getting the lay of the land for the gaming tablet scene (works will for all of the Biz travel I'm doing right now, too).
Right now, I'm working through a ton of RPGs -- like Zenonia 2 -- looking at how they're taking advantage of the form factor, evolving the genres, and (if applicable), improving across sequels.
Zenonia 2 doesn't do much over Zenonia, and while it's a solid enough RPG offering, I found it's navigation a bit frustrating, and it's slow pace and exposition akin to Advanced Wars -- but minus the charm.
I'll be playing through it (and hopefully the third and fourth iterations of the franchise) to see what I can learn from this mini case-study for how to provide gameplay experience for genre fans on tablets.