This is an interesting one.
This game disguises itself as a sidescrolling shoot-em-up but in reality it plays more like a top-down twinstick shooter, the only difference being the pretty collectibles, the sole evidence of gravity in this game, who's main purpose is to lure me into taking damage from colliding into the floor.
Originally I was going to say that I really didn't like this game, that you have all this nice art and polish but the core gameplay wasn't fun. That was my impression from the tutorial level. And you seemed to be falling into the trap of adding-more-mechanics-to-make-it-fun. I really don't want to learn and have to manage 8 different mechanics to play a 2d indie shooter.
I had a problem with the Robo-Templar game for very similar reasons.
Then I tried out the second level (The prefab test level?)
I sincerely hope you make the entire game like that level. I don't ever want to manage a gun, manage my shield, any of that. I just want to fly around, dodge bullets, and watch the explosions.
I guess it's something like a vampire-survivors-like, with maybe a bit of autobattler? Maybe this was your intention all along, but I went into this thinking I was just going to be playing a regular shmup. In this vein I think it might be worth considering leaning into this more, with larger, more open areas? I see you've been working on this a bit, maybe that's something for a sequel.