I checked out your game and here's my feedback:
1) The art style is really cool and minimalistic. I liked the sounds on the title screen and I generally enjoyed the vibe.
2) Great job on the way you've setup the first few levels as a tutorial. Clearly you're setting up the level to practice the mechanics being presented and it felt very intuitive.
3) I really liked the music and wanted to ask you where you found it btw or if you made it yourself. The main loop got a bit repetitive after a bit but its still overall very chill.
4) The character's movement feels a bit too floaty, that could be on purpose but wasn't sure.
5) The camera might zoomed out a bit too much, the characters are cute and I felt I wanted to get a closer look at them.
6) The character's attack needs a bit of work in my opinion, the range is very small and to be perfectly honest I'm not sure what it is that he's throwing at the birds :P. Maybe you meant the range to be small but I found it frustrating how close I had to get to the birds to hit them. Maybe increase the range and make the birds chase the character if you get close?
Still, it was a nice experience. Really motivated me to stop dithering and release a playable vertical slice for my game :P.