The background music was really good, and I liked the colour scheme and simple graphics ☺️
It took me way too long to figure out that something was happening - I thought it was just a dodging game, I didn't realise my bullets were doing anything. It doesn't really feel like anything is happening! Same when the player gets hit. It could do with some extra oomph when things happen. A bit of camera shake, some screen flashes, maybe flash the health bars when they go down, make the player hit sound effect louder, that sort of thing!
That said, though, the patterns were really well designed. It was a lot of fun to dodge them, maybe focus on that if you do a full release of it? Get rid of player shooting entirely and make it all about dodging :)