Chou Shoujuu Mecha MG
japanese mecha game, but easy to figure out.
you need to complete simple missions using mecha which are partially touch-screen operated(sounds bad, but the touch screen is actually what makes it not so bad)
or if you're more interested in medabots-like mecha: custom robo arena.
RPG where you use remote controlled pocket-sized mecha to hold 3D arena fights.