Owners of Kerbal Space Program are in for a treat as the newest update brings the game to 0.17 of Alpha and introduces many new features.
Kerbal Space Program is currently under development, but already offers a solid play experience as a sandbox.
This is a full version update. The 0.13.3 version is available for free as a downloadable demo, but only the full (paid) version will continue to be updated with new features.
You can order the full version of the game now for $18 USD. This amount will increase as development progresses, so by ordering early you can get the game at a very discounted price.