Autocraft is a physics based puzzle game about building complex machines to accomplish objectives. You build a craft for a specific challenge. Each level also has unique secondary qualifiers like; only use 3 wheels or make a vehicle with only 1 rocket and so forth.
It ramps up the difficulty with each level. At first you are simply coasting down a hill, later on you're rocketing around and making vehicles that can jettison parts away.
You'll end up faceplanting a lot but through each scrape and crash you'll learn more about the environment and how to make better vehicle. Or, maybe you won't learn and you'll keep crashing over and over because you're having so much fun.
Your vehicles are only limited by your imagination. Well, that and the part restrictions per level but you can really make some wild things in this gem of a game. I've only scratched the surface.
There's also a sandbox mode where you can make whatever you fancy. I'm still nibbling away at the challenge mode.
It all starts to come together in an awesome mix of playful engineering and puzzle solving. Learning the limitations and tolerance thresholds of the physics and gravity mixed with the fragile stability of your craft is what keeps you coming back.
Autocraft is in Early Access. Buying the game from their site gives you a Steam key to redeem. *I'm assuming it will be sold on Steam soon.