I liked it! I think that you are going for a slower overall game pace than I'm used to with shmups, which is fine, but I think that it becomes a liability, especially because things take a long time to happen (section length is long, bullet speed is VERY slow, ship speed is slow, etc), and without that quick decision making shmups often rely on, it feels flat.
Also, the problem with a lot of the powerups is that most of the time, they felt like hindrances more than help, especially speed-down for something-up items, which in a game where the ship speed is already slow and the hitbox is very big, feels like certain death.
Visually, I think the game is really nice! Again, I think having different bullet types for different enemies would help a lot, but besides that, I appreciate the variety you put in the sections, and my only wish is that you would mix-and-match enemies to complement each other.
Can't wait to see the final build!