High score of 49! Which, considering I stink at bullet-hells, is pretty great for me!
I literally had the thought at one point of "Hmm, this is actually quite easy" and then all of the sudden I was surrounded by red bullets, so idk how you managed your difficulty scaling, but it's perfect! At least, it was for someone like me who doesn't play these kinds of games well or often.
I do wish there were more areas that blocked bullets, or maybe places that didn't block bullets but did warp your connection to the other cat to offset you. That's a big empty space in the middle you got there, and it's just begging for some kind of central something or other.
This game can start to feel like I just have a two bullet gun things instead of two separate beings who are joined together. I think adding more places where you're kinda forced to offset the cats would help with that, but really anything that you can do to help them move just a bit independently of each other would help with that.