Ok so to get this out of the way, did you or your team make the music for this? If not then it sounds like it's just some ripped Touhou arranges, which isn't allowed for this game since you can only use royalty free assets if they aren't yours. I'm not gonna bring upon any dire consequences but just make sure to read the rules next time.

Bue anyway, ayyyy first game! And it's nice, and cute! Besides some technical stuff like making textures that loop better and the second stage bg being kinda weird, it was some nice visuals to look at and really solid for a first go at make games (my first game looked so bad). The first thing you should look into is some simple restrictions and details that are subtle but necessary when making a game: like making the bullets disappear when they go offscreen so you're not killing enemies way off the screen. Also some of the levels did overstay their welcome and could be more densely packed so there's no large empty sections, but at least the music was nice so it was just kind of a relaxed slow game (but again please don't steal if you did that). For what the game attempted it was a great start to making games! And you can only go up from here as you get comfortable and learn how to fit more in a game and take advantage of great mechanics. I look forward to seeing future entries if you plan on joining again!

The concept was good and Aya's sprite is very cute, the music choice for this is really good too.

There's only 2 things that bothered me

1- Enemy placement: I could often hear my bullets killing enemies offscreen, leaving me with nothing to do if I did so.

2- Credits: It really needs it, I didn't knew I was finished the game after defeated the boss lol.

Not too bad for your first game. Don't feel discouraged by all the other cool games. in the jam and just keep at it~