If you've played Captain Forever, you've got a basic idea of how this game works. Roll around, kill enemies, snap their parts to your vehicle, rinse and repeat. The difference is that instead of a top-down, Asteroids style game, TerraTech is a 3D, physics based game, with some extra resource gathering and crafting elements.
You also have a base to protect, bring resources too, and craft from. Resources come in the form of trees, rocks, and various precious minerals, and you collect them by shooting at them, attatching drills or other tools to your vehicle, or even by just getting a big enough car to plow through them. Resources are not stored in any sort of inventory screen, but instead get added to a "stuff blob" that floats above tractor beams in your base or attatched to your car.
The game is still in fairly early development, and any problems I have with it at the moment have to do with the unfinished parts, which will be cleaned up as development progresses. I'm really excited to see where this game goes.
If you want to see the game in action, I've recorded a bit of it for my channel, which you can check out here: https://www.youtube.com/watch?v=zz3pda_N_3E&list=UUBo9F0FU148NjZOJFN7rrGQ