Tablet/phone games are fun, but a few things bug me for extended periods of play time.
Yes, touch screen is nice/cool for some games, but the main issues are always present:
1) your hand/fingers block your screen/sight/view
2) no physical feel for the buttons (for like moving/jumping/attacking). Sometimes my character will stop running and die from being attacked b/c my thumb "slipped" off the on screen joystick and I didn't realize it.
3) Ergonomics - Since the tablet is kinda heavy, you lay it down and have to look down at it at an angle which hurts my neck after a while. Or if I want to hold it eye level, I have to put extra strain on my arms/wrists.
Having said all that, some fun games are:
-Where's my Water?
-Elf Defense
-Cut the Rope