Thanks for the feedback, Humane Tiger! I really wanted to make the experience as simple and as clean as possible!
I never played Kerbal Space Program, but I have heard nothing but good things about it! Mabye it's time I finally give it a whirl!
If you like astro-games, orbital mechanics and really tough challenges, you have to give it a try. But be warned. I once found a statement about this game - can't say it better than this: "KSP doesn't have a learning curve, it has a learning wall!" :-) But it is so rewarding digging into it, can highly recommend.