This game is very easy. The aiming is incredily more so because if you use the arrows/space bar to control the catapult, you just have to adjust for when they move which isn't difficult at all. All you have to do is a get a barracks and keep sending those troops. That can beat any level.
Yeah I find those that rate a game low because they suck at it or because of some glitch need to find something better to do. or just gain gaming skill lol.
The easiest way to get ether fast as possible is to get the smart missiles FIRST. From there, get multi-shot and continue to upgrade your cannon. Just sit near your station and pot shot for loads of ether. Do NOT upgrade your troops as if they do nothing, you get all of the ether. Secondary shot isn't very effective till you go to take out the yellow blob things. Get max shield before you do that. Then get Repulsor shield and upgrade allies while nuking yellows. I beat it first time.