This game is being developed using the ShiVa game engine. We have been prototyping on the Nexus 7 and Windows using an Xbox 360 controller.
The Nexus 7 gives us at least some idea of the draw calls and fillrate we might expect from the OUYA. Performance analysis of a device that you don't have is difficult, we're currently looking at a 30 draw call maximum and about a 60k triangle limit to maintain 30 fps.
We hope we'll be surprised by the performance boost on the OUYA since it's the upper end Tegra 3 chip and can overclock without worrying about battery heat. Still, we're not sure if it will be enough to allow us to use water or real-time shadows that don't suck. These look amazing on the PC, but PCs have that advantage since their discrete graphics cards are easily 3-4 times the size of the Tegra 3 motherboard.
The game is still a work in progress but we have enough finished so that we can build levels in the level editor and play them (yes we are shipping with the level editor). The core game mechanics like ship physics and collision are complete and we hope to have a playable demo soon.
If you have any thoughts we'd love to hear them!