I found rocket launcher to be best secondary for that boss (something Prime?) and possibly for all situations. Except level 5 boss. It's stationary so just stand there with Laser and it's fucked, not too hard to avoid bullets.
Man, losing lives / power in later levels makes the game tortuous. So hard with nothing but a dash and single bullet line with no range.
Still can't beat Supreme AI. Any tips? Obviously getting to it with max power and decent secondary is ideal, but I'm not good enough for that. Confuses the shit out of me on second form when you're surrounded in a laser.
Haven't played this for most of the week due to Horizon, but decided to finally 'complete' it on Experienced. Actually got to the level 5 boss on one credit and had it down to a third health, but then lost 4 lives in quick succession. By the time I'd finished level 6 I'd continued about 7 times.
There are some annoying parts in the last couple of levels, especially on the bosses, where you can pretty much die immediately before even knowing where you are. The last boss itself isn't too bad (with a rocket launcher), except for that it's hard to see where you are sometimes. Lost a lot of lives just from losing track of my position.
I think a 1CC is doable for me with a bit of practice, and if I don't give a shit about score. I can pretty consistently do the first 4 bosses without losing lives now. and even got through most of level 5 fairly unscathed.
Got halfway through world 6 last night, disappointed. Basically lost all 6 lives on one stage. After losing first life, I got hung up in making sure I make it to my lost power up. As a result, I kept fucking up and got lasered multiple times.
Wasn't concentrating on score but managed a personal best of 87m. That's way off JonB's 170m or so!