Good game but....
Once you get to the levels that have 20+ enemies that can fire from anywhere on map... it starts to get impossible, i tried bombs, i tried cannon fire, everyting i could think of and couldn't keep up with them shotting the lab from 100 miles away 4 at once, and my speed was i think 5 or 6 in speed and accel, so i was fast but still couldn't keep up... work on the balancing and this game would be 3x as good! :)