It's likely ARM. My guess is ARM Cortex-M4 32-bit (Can't confirm)-- But you're best bet is to utilize the SDK and its APIs to handle interactions with the device's hardware and sensors. To my knowledge 3D currently isn't fully supported. I'm not saying you couldn't do it or even do a raycasting engine for it, but you're best bet is to not over complicate it and work with in the limitations utilizing the controls (design of the cube) for your game.