I couldn't find where the creator mentioned it, but in Giga-Robo team play (2v2 or 3v3), if a robot is destroyed, that robot's pilot can "jump in" to one of the remaining robots, contributing their spirit and pilot cards. Which is super cool, because it means that the fewer robots on a team, the more powerful they become.
But it's also cool because you can presumably play this way in a 1v1 match. Let each robot have 2 pilots (ala Pacific Rim or Gurren Lagann), and build your deck out of those two pilot's instants (plus the robot's cards).
I'm hoping someone can remind me of the particulars of how a two-pilot robot works in team play, so I can have it straight. I think when you "power up," you can gain spirit equal to BOTH pilot's heart, which means the match would be much more accelerated than a normal match. Which would be both awesome and possibly unbalanced. But when two giant robots driven by rage and laser-punching their way through a crowded city, occasionally a little unbalance is fun.