The Ambiance alone is enough to favorite this game. chilling music from the start foreshadows what you're getting into. Your first loss teachs you just how unforgiving the levels are. With Decent graphics coupled with equally decent script(I mean this game isn't gonna win an academy award), this game gives you an excellent experience while still being entirely free to play. This game, however , is not without it's faults...
I'll start with my biggest problem, the Fuel launchers. They are far too expensive for what they do. Not only that, they are entirely useless and redundant. The Flare gun's alone, when you get 6+ of them, are more than enough to deal with the bursters that the Fuel launchers are suppose to stop. Not only that, Burn damage is far too slow for how quickly enemies need to die in this game. I mean NEED to die as in you wont win if you dont kill them that fast. Other problems would be redundant support powers(why would I use a machinegun flyer when I could use a pulselazer, why use pulselazer when I can use ship lazer, why use any of them when I can use far less money by spamming graviton pulse) and lack of useful UI features, such as a representation of your total cone of fire. You really have to eye ball every unit you place. Accidentally leave a few cones not overlapping enough pixels, you can expect a runner, or worse yet a hunter, to squeeze through there and rek your day. For free experience, however, this game is far superior to most games out there to be played free online.