Would be more fun if there was more variety. For examples of this, check out this similar avoiding type game called Squares 2 - http://www.albinoblacksheep.com/flash/squares2
Needs more variety in weapon selection (perhaps faster firing rates, a spread cannon, etc.) and something that makes the player feel like they are progressing and not just shooting the same asteroids the entire time (put in different bosses every 5k in points?)
I'm up to Wave 10, this is my fourth time though since the bug and difficulty fix, and the best strategy is to NOT get helper cannons, but rather just spend your upgrades on damage increases. Helper cannons do not do enough damage and their upgrades are too costly.
It also contains a bug when you buy the extra cannon. Now my first original cannon does almost no damage. After buying the second cannon, you will immediately lose the next stage as all your previous upgrades disappear.
I updated my rating to 2/5. The first boss is too difficult and there is no option to redistribute points once spent. If it wasn't for the card, I might not have given this game another play (I played it once before the card then forgot about it).
Great game, 5/5. One suggestion that won't affect gameplay but will make things easier: instead of putting a star next to each map name when one hovers over it (or rather in addition to that), put a check on top of each completed section and something else to signal that a level still needs to be complete. This way when one comes back the next day, they don't have to search all 20+ maps to find out what they still need to do. Thanks