I'm pretty happy with the UI, I find it pretty easy to navigate and with the built in search I can find a specific game very quickly. I'd like to be able to easily add side loaded Apps to my main Play Menu, and maybe have it automatically split games and apps into separate rows for me. I like the OUYA color scheme, but it might be fun to be able to add custom wallpapers in the future, perhaps game devs could add wallpapers we could use?

I'm not sure I agree with the word "fixed" in the title of this post, it's very subjective. I see myself as an early adopter and the OUYA as an evolving product with a lot of growth potential.