Loved the game, unfortunately it glitched on me at the beginning of level 2 and the for the rest of the game the soundtrack was accompanied by an irritating whining noise :(
Once you're past lvl 8 ish (so you have the class 4 tank size and mega cannon) try building a class 4 tank with just one large bubble right at the front (that is, right at the edge of the class 4 boundary). Add as many mega cannons as you can afford (1gp for 4 damage) arranged in a rough circle just slightly off of this bubble's centre. And voila, a tank that does LOTS of damage, moves a little slowly but is small, and can do parallel fire (mouse cursor far away) or spread fire (cursor very close to the tank)... makes this a game of patience, not skill.
I like the concept and the animation, but I see no reason to complete the levels more than once - or indeed at any particular speed. An upgrade, trophy or achievement system needs to be added to give some incentive to replay the levels and attempt reckless stunts! Without it the game feels short and somewhat incomplete.
I had the same problem Alblaka had - got stuck on the level with the red and white dog-things because the firefly wouldn't do the action (the timer-cursor just got stuck on)
Played it before the update and enjoyed it, played it after the update and found the whole thing had suddenly got a hell of a lot harder... and subsequently less fun. I can't stand games that require excessive grinding in previous levels in order to progress.
Been playing this too much on pattern: straight, motion: wave - my brain keeps insisting that the whole screen is moving up now =/
But other than that, ace game :D 5/5
 "Aurora"){kind=icon}
 "Heir"){kind=icon}
 "Bubble Tanks Arenas"){kind=icon}
 "Neon Rider"){kind=icon}
 "Sushi Cat"){kind=icon}
 "Mogo-Mogo"){kind=icon}
 "MegaDrill"){kind=icon}
 "4 Differences"){kind=icon}
 "SkyFyre"){kind=icon}
 "Pixel"){kind=tracking}
 "Bunni: How we first met"){kind=icon}
 "Music Catch 2"){kind=icon}
 "Understanding Games: Episode 3"){kind=icon}
 "Fantastic Contraption"){kind=icon}