Wanna build space games? Here you go!
Flight Sim Toolkit, as the name suggests is a set of tools and game creation goodies that will help you create a well produced and well polished (for a non professional gaming production suite!) space game, as long as you're in for spending the required amount of time required. At any rate, with Flight Sim Toolkit you don't have to worry about being greeted by a very complex toolset. A lot can be automated and the fact that this is a space game is done by already packing a lot of prebuilt assets. You can also use a randomization string for a lot of the game creation and so, you could have the basis of your game in a short time, and from there, all you have to do is just start adding detail. You could end up creating space shooters, 4X games, or anything in between. Not a lot of scripting tools, so that might end up hamstringing your production, but ultimately, what you get, is a great teaching experience. Anyway, have AGS around as well
, for a more general purpose production tool as well.