Excellent work!
The top review on the page was a bunch of naysaying thankless gibberish, so, since i played this and found it quite enjoyable, I thought I'd go ahead and write a quick review.
The only thing that I would change about this game, is I would make it just a little more difficult.
Beyond that, everything is well done... well thought out game dynamic using XP and having a Base and yourself to worry about. Kind of like other base defense games with a satellite instead of just a base. I really like this concept.
You show excellent potential as a game designer, so, keep up the good work, and thanks for the awesome game.