I hardly notice a difference in reload speed or damage from 1 to 5. Game looks great, but the upgrades don't feel like they do anything. By wave 15 I was getting bored.
Even grazing an object often "sticks" you to it, spinning you around the object you're stuck too, ruining your whole flight if something bumps you. this should be fixed, it's very annoying.
Too many little random things can kill you, sharks behind the rocks come out of nowhere, weight resetting when you die is dumb. The first two were better.
This game is fun but it went from "people eating game" to "shark dodging game" real quick. You shouldn't have levels where there are more sharks than boats. Also, make it so sharks don't come at the same time as boats so you don't force the player to choose between dodging or eating.
Awesome game, I love it. The only critique I have is that Pause is a little TOO powerful. I think you should make it more expensive. I abused it to win the last song.
If Penguins can get stuck on walls it's really crap and unfair that Turtles can shoot through walls. Fix the broken penguin AI or make Turtles unable to shoot through walls.
Great game, but there are a few issues. You should be able to sell units, or move units you already bought back into your army. Also, having limited "losses" available is not fun and a big turn off.