So I stumbled upon this new game just over a week ago, called Kerbal Space Program. Basically what it is is a sandbox space exploration game, where you build your own rockets and fly them to space (which is surprisingly more complex and amusing than you'd think), with the clever exploitation of orbital mechanics and other physics-related stuff. It's still in alpha, and thus in very early development, and yet it is becoming more and more popular. The growing community is also very friendly. Here's some personal screenshots of my greatest accomplishment so far: landing on the Mun (the game's rendition of our moon)
You can check out the official website at
https://kerbalspaceprogram.com/ , and also note that the game is available on Steam now.
Just trying to spread the word and help this game get off the ground - it's one of those must-buy indie games. Remember that new features are constantly being added with patches, and there is much more to come! Hope you enjoy it as much as I do.