If you are facinated by space and enjoy the concept of making your own rocket and landing on other moons and planets, i would recomend you try Kerbal Space program.
It is really cool!
HERE IS A SPACE STATION I MADE
[IMG]http://i.imgur.com/nh2odci.png[/IMG]
Landing on the moon
[IMG]http://i.imgur.com/xeJ1F.png[/IMG]