Really hard game! I would have appreciated a way to get to the level menu from within the levels. The first time the flappy-bird mechanic is introduced I was really surprised ^^. I like how you switch up the control/movement schemes to get multiple experiences out of one level. As mentioned by others, the physics could really be improved upon. Part of what made this game hard was some of the physics unpredictability, or how quick you started to fall/fly up.
Nice effort!