I didn't think it was possible to make a defense game this bad. Instead of just clicking and throwing you have to hold down the button while the aiming circle travels to the enemy. This makes every single throwing weapon extremely hard to use. By the second level you're fighting a dozen enemies at once and since it takes so long to target each one you simply can not win.
The levels could use better design. I got stuck on the 3rd level because the top gravity arrow is too hard to hit. It is not where you would naturally go when simply spring jumping.
All you need to win is dart towers. Place one then upgrade piercing. Place a second and upgrade piercing. Repeat. After about round 25-30 you can upgrade them all with range too.
I just used 3 full clips of the AK47, a weapon with a very high accuracy stat, and didn't hit one enemy. Missed with every single bullet. Sometimes even grenades miss when they explode on top of the enemy.
Buy Assault Rifle. Upgrade reload and clip size. Max strength. Buy 1 engineer. Buy 1 rifleman. Buy sniper rifle. Upgrade everything on it to max starting with clip size. Buy 2 riflemen and 2 engineers. Buy the chaingun. Upgrade clip size once then strength as much as you can. It is impossible to max the chaingun because you win after level 30.
Nice idea but it suffers from massive game balance issues. The first stage has taken me over an hour now because the enemy ship has about 40,000 combined hp and shields. Also the more ships you make the WORSE you do since the enemy has an overwhelming response. This makes the game very very boring. Overall 1/5 - besides an interesting idea this game just doesn't have much going for it.