Some difficulty problems!
Without a doubt, this is one of the best shooters I've played here for weeks.
I mean, what else do you want if you have a glorious 8-bit remix of a glorious rock song as your main theme, well-polished retro graphics, challenging levels, an original upgrade system (probably not unique, but rarely found) and extremely funny voice acting?
The only things that prevent you from getting a 10 are:
1. The ship having the same colour as your weaponry. This is quite confusing at times and lets you waste several lives, because you can't focus your ship.
2. Not so well-balanced difficulty. After level 3, the learning curve is much too steep and upgrade loss punishes you quite hard. Good thing you can always try again with the original level setup.
3. Passive resister medal. From what I've calculated by measuring the boss's health bar, you need 9 bombs and 6-7 lives (+1 for preventing game over) to defeat him. Even without considering the fact that this medal is only worth 25 points, this is sadistically hard.