Damn, once you get the shield you're hard to kill. I wasn't trying all that hard and I got a nomiss. Played with autofire on shot + bomb, can't be bothered to wear my finger out button mashing the entire game. Was kind of surprised the game didn't loop, the final boss didn't look terribly special and suddenly the game's ended, and I'm like "oh, that's it?".
I think there's an optimal route you can do to kill a boss on every stage for a higher score. It's pretty insane once you die and loose your power-ups IIRC.
Yeah, recovering from a death is quite hard late game. You lose so much spread, movement speed, and the extra abilities the powerups give when you pick them up while maxed out (blue gives you a shield, red/green kill all onscreen enemies).
You could probably get a better score just by suiciding a few times too as it uses checkpoints doesn't it?