Amazing! Albeit a little samey..
Almost perfect, except for the fact that it's a little samey. Great concept, and all round just great fun.
Also, I've discovered some cheat..
On the upgrade screen, type VCX, and you'll have 100 pts to spend. Repeat where necessary.
Also, in game, while playing, if your energy gets low, type MVB to get your Hp back! :D