Nothing. I love it!

I hate mobile games with fake D-pad/thumb sticks, and buttons. Its really hard to enjoy games with controls like that on small phones because your thumbs can cover the entire thing on the screen.

I mostly play puzzle games on tablet, there are more than a few that are quite good, and generally speaking, it seems those games have most success both on iOS and Android.

Action games tend to be bit tougher to play, due to lack of at least joystick, but if Apple goes through with their pop-out joystick idea and starts making devices with it (and everyone else copies/come up with something similar), it could change the way lot of people are treating mobile gaming.

One other genre (not so much a genre actually, more a category) could be interesting, since there is not much games there - local multiplayer games. I have few of these, mostly to play with kids, they go from board games (Pirates, Through the Desert), racing games (DrawRace, Slingshot Racing) to turn-based affairs (Hey, That's my Fish) or real-time "strategies" (Starlink).

Well, the touch controls often put severe limits on what kind of gameplay you can implement without too much fuzz and clank, concepts such as Angry Birds are immensely simple and straightforward and that's usually not my thing since I mostly enjoy more complex games since it is something I dedicate a lot of time to rather than play in short bursts on the bus or at a friend's house or while taking a dump.

The "no meat to the core structure" essentially revolves around the same issue as above; the concepts are usually made deliberately simple and easily digestible to appeal to its main audience; and I am not in this audience.

I don't hate all mobile games... but the main reason I dislike most is because of microtransactions and the repetitive basic gameplay.

You asked for it....

Controls most of the time.

Mobile gaming is evil. EVIL!!

Nothing good about mobile, of course unless games from mobile make their way to my 3DS and/or Vita.

Like many my main complaint is because of the limited controls, but that's really not developers fault but hardware's limitation.

Some simple games, like Rayman (mobile version) or angry birds can work really well but those are boring for experienced gamers who like advanced and responsive controls in their games.

And it's not only because of 3D, second stick for camera, analog controls etc. For instance something like Guacamelee could never properly be ported on a phone, and that's a 2D game but it need lots of responsive buttons which enhance interactivity hence immersion.

EDIT: But puzzles & interactives games can work with simple controls on mobile.

Too casual + physical controls > touch