Interesting concept. Definitely would like to see more development on it as a whole.
Feedback:
I think it could be more fast paced because it is too slow right now just waiting for the birds to hit the edge.
If you had something where the movement was fast and you also implemented some point and click for direction of movement when you press space that might be a nice touch.
I recommend reworking the animations and also varying up their positions and where they land.
Maybe when they hit the walls and bounce off that could be a chance to perform a special attack to dash into enemies or items.
I think it would also help if you had some nice music in the background along with the sfx you have.
Over nice work though!