It's fun if you like this kind of thing. I love astronomy, so it is really interesting to watch. Note that there isn't any music and it is almost entirely a physics simulator. You can do stuff like crash planets into each other and stuff like that, but it isn't really flashy or anything. If you like space or science in general, you might enjoy it. --- Sometimes life leaves a $100 on your dresser and makes you happy, then you realize that it's because it just screwed you.
I was about to buy it at full price, so the sale is a pleasant surprise. The one guy who made should get quite some money out of this. --- Another idea I had was the spy/sniper being able to climb into the soldier's rocket launcher and be launched across the map, dealing more damage, but no splash.