Hello, I am getting KSP for my birthday : and I want to take a sneak peek about the early days of ksp. How do I get those early versions? Taken from http://www.kerbalspaceprogram.com : The game is currently under heavy development. This means the game will be improved on a regular basis, so be sure to check back for new updates. Right now, KSP is in Sandbox Complete state, but we want you to try it out and have fun with it. The first versions are free to download and play, and will remain so forever.