It was during the same time that Zoids, Yu-gi-oh etc was out, so late 90's most likely hearly 2000's. It was about a team of people that had control of these mech-suits (like the ones in Avatar). They would play team-based games like capture the flag and stuff, and they have tank-track feet to move around, as well as walking. I remember one episode they fought a giant T-rex dinosaur. And that the bad team were in black mechs.
It isn't Gundam, transformers, zoids, voltron, avanlgion. I've looked on loads of forums and can't find it.
I think it was either on Sky or the main 1-5 channels. Though it could have also been on CN or 2 other channels that had things like Naruto etc.