Not that good. Game boils down to beating initial contact then telling the game "yes send all units in and over power" again and again. I watch more than I play. units also double spawn many times (unless this is intended, if it is game doesn't make this clear).
Bored to tears. lackluster, repetative, simplistic. no skill involved. you pick a higher value every so often. not worth your time. I DID try to give it a chance. 500 levels... nothing changed but a couple numbers. Fail.