I can totally see this being a a full game, with upgrades to the burrow's wheels, Okuu's cannon and Orin's legs. Plus 7 different outfits for both and an EX boss, and in FULL 3D!
I'm thinking of games like Battlefield: Bad Company 2, where you can be in the jeep with the guy who drives and the guy who fires the grenade launcher in the back. (Or the Warthogs from Halo, if you go further back...)
Mobility + firepower - any form of armor or hitpoints = massive quantities of fun.