TerraTech is one of the more interesting sandbox games I played last year, an open-world giving you a lot of freedom to explore and destroy while you create your own vehicles.
Just last month, they put out the 'Better Future' update which is a whole new corporation for you to deal with. They come complete with their own set of building blocks, many of which include anti-gravity for you to really spice-up your creations.
Have a look at their update video:
Another addition in this update is the inclusion of multiple control schemes, which you might find easier to switch depending on what type of vehicle you've made.
The Linux version continues to run rather nicely and I'm pretty excited to explore some more and get some anti-gravity vehicles going, sounds like a blast.