The OUYA's storefront gets so bloated with shovelware that it's easy for really good games to get lost in the shuffle. One of the games I hope that doesn't happen to is Kosmik Revenge. It's a free-to-play Space Invaders clone with a more modernized hyper-stylized look. There's a ton of Geometry Wars Evolved-style lighting going on with some solid pixel art with impressive shading on the enemies and throughout the game.  A paywall is instituted for extra items and things like extra lives, but for free, you can play through it if you're able to do so without a continue. The pace is a bit faster than Space Invaders, so if you find that game boring (and that's fair given that it's incredibly old now), then this might be more your speed. Much like how Breakout clones have taken an outdated concept and improved upon it, Kosmik Revenge does the same for the Space Invaders formula.

https://www.anrdoezrs.net/links/3607085/type/dlg/sid/UUhgUeUpU53575/https://www.youtube.com/watch?v=tT0aD9No9lI