Very addictive game. I used the beyblade laser strategy: increase main laser damage + rotation speed and rotate indefinitly at the center of the arena :D
First game over at 230, but then I kept my updgrades from the previous run. With all the cumulated updgrades I was bascally invicible, and I let myself die at 629.
I love the enemies and the background art!
The upgrades that can be destroyed by enemies is a nice touch.