Scrap Mechanic should be lot of fun
Robocraft is one of the first games of this kind, where you can build your own vehicle from scratch. Than we had introduction of TerraTech on Kickstarter and now new similiar game is announced called Scrap Mechanic.
You can guess from title what kind of game is this. Main task is to gather materials so that you can build your own vehicle and than later you can try to drive them and have fun with them.
If you like this game and want to help, head down to game Steam Greenlight page. Check the debut trailer: