This game is fun, and bears a lot of similarities to the game Paper Plane.
The collectables are an interesting addition to the game, but unfortunately they are completely random. The fun of Paper Plane comes from the demand of precision, and you've captured that excellently here. The collectable addition seems more like an addition rather than an integral part of the game because the player really doesn't have much choice on whether they collect them or not. At the end of the day, the player MUST keep the bird alive, and they CAN get the collectables. That means that they're never really incentivized to go out of their way to get collectables.
I like this game, but I think you could add some more unique mechanics to spice it up.
Great job!