Really nice art! Especially the technical aspect and implementation. The eyes looking at the cursor is a detail that really stands out and adds value (Actually we thought about adding something like this to our game haha). The transition between menus is also very well done, and the gameplay also has some nice effects, not only visual but also how the gameplay and movement feel.
As for the gameplay, I found it very easy to confuse the character with the collectible bubbles and, especially, with the enemies.
I really liked the idea of shrinking the play area, although it took me a bit to realize it was happening haha, maybe you can make it more noticeable.
Regarding your question, if I had come across this game on a regular day (by the way, it's a very good question), well, I guess it depends. I think it would have caught my attention on mobile and I would have definitely tried it. Currently, I suppose it's not designed for that platform, but in my opinion, it could work very well. I don't think there's any reason for the player to stop shooting, so it could just automatically shoot in the opposite direction the player is moving (that would also solve the problem of unintentionally clicking upgrade buttons). It's something I've seen in other games, and I think it would work really well in this one (I wish I could give you an example now, but my memory sucks, sorry).
Overall, very good work! It's clear you're putting a lot of love into it. Keep it up! Good luck and I hope the feedback helps!