When I played the other games I felt like they were complicated and hard to know where to go or how to do things but in this game I instantly knew what to do .. shoot eggs out of my bird mouth at the clearly evil backwards flying birds in front of me haha. The controls were very intuitive and the fast birds gave me a spook. The pixel art splash screen is amazing.
I think the UI could be cleaned up, and I think I was on level 2 for like 8 levels.
Add some bird music. Maybe some egg sound effects.
Maybe an awesome boss bird, like an eagle or a hovering penguin.
Awesome start!