Nice game! I appreciate that you had a nice gameplay arc of progressing from single hit enemies, to mixing in multi-hit enemies denoted by green feathers, and finally a big boss.
I wished that the gameplay would have another dimension to slowly scanning trajectory lines for a winning shot though. That kind of gameplay felt a little samey towards the end. One more small thing- the gunshot sound is very loud, it hurt my ears haha.
Overall nice job! I think there's potential to be explored here.