1. I have never had a problem with their controller. (I have read that they fixed some stuff after the initial release of the system.) Then again you can use the PS3 controller, an added plus.
2. I know this will seem long winded but I am trying to answer your question. I am a retro gamer. I am finding a lot of stuff that scratches that itch. I enjoy one and two button gaming and prefer it to the present generation consoles where you use every button on the controller. I love arcade type gaming and loved its influence on the early Atari, 8bit, and 16bit systems. You must keep that in mind. A lot of the games remind me of 8-bit and 16-bit gaming with graphics comparable to original gameboy to PS1 or slightly better, depends on the programmer or team. When you open a system like this to everyone to program for, that in and of itself, brings some limitations as to what a person or small team can and will do, and it reflects in the games that are available. I do not have a smart phone, so I do not know what is available on both the Ouya and the phone.
I am finding a lot of good old school type shooters, some good platforming, and puzzle games that I really like. They are simple games, but they are fun to play. Some people have got some nice ideas and they are talented. I really do not spend my time on any of the emulators.
A short list of some of my faves,
Teslapunk
Raiden Legacy
Siine Mora
Ballistic- love this sort of stuff
Inferno+ 2- love this sort of stuff
Reaper
Heavy Recoil
GunSlugs
Tennis in the Face
EFMB
Super Crate Box- this is totally insane fun
Pix'N Love Rush
Chronoblade- in which I wished they would do more with this concept
And the game "Hero of Many" I cannot even begin to know how to classify that game, but it is fun. Its exploratory puzzle elements captivate me.
I could list a lot more that I enjoy. I purchase games on this system which I have surprised myself in doing. I am a touch it, feel it, sort of gamer.
If you are really into the present generation gaming complexity & graphics of console gaming, then you may be disappointed. The Ouya has my attention while the Wii sits on one side and my Daughter's PS3 sits on the other gathering dust. Then again you need to understand I am presently enjoying playing my original Gameboy games too. :lol And the answer to my wife's question this week as to why? Because it is still fun.
3. The emulators work surprisingly well. But I do not spend my gaming time with them. To me, they are not the main reason for owning the system, I can see that for some it would be. Neo Geo works well from some of the games I have tried.
4. I don't have working knowledge of cell phone games. If you did not play because of screen size, make it as big as the TV you have in your house. My gaming experience with the Ouya has been fun. Just keep in mind what I have said above about my taste in gaming.
5. When I sit down to do gaming on my flat-screen in my family room, it is going to be the Ouya. There are games on there I can play for a few minutes to an hour. If you like simple addictive stuff from the golden age of gaming. I think it is worth the price of admission. I have not regretted my investment. I am a happy camper. The Ouya is for a niche market, not for everyone. And I would not compare it with the PS3, Xbox 360, or the Wii. It does not fit in that group, or camp. Not sure if one could consider it a complementary second system to those consoles or not. It would be a matter of ones own particular gaming tastes. I love having my Ouya and would not want to do without it in my gaming. I give it a big thumbs up, but that is me.
I hope, in one way or another, I have given some sort of idea, or more than just a vague answer. It is sort-of difficult to answer some questions. It is sort-of like reading a gaming magazine with three people giving their opinion about a game to the whole population of gamers. Reeeeeally? Whelp....! I have always scratched my head over that one.
Do feel free to ask more questions.