If you like Cybernator, try the FUCK outta Metal Warriors. Developed by LucasArts, it has Cybernator's gameplay and mechanics with destructable environments, the ability to get out of your mech as a little dude with a peashooter and a jetpack, and hop into enemy mechs with entirely different abilities. It's extremely hard but extremely cool and ambitious.
Seconding this. I've never played Cybernator but I immediately saw the resemblance to Metal Warriors. That game was fantastic.
Xel's comments