Feedback & questions:
1. Maybe a subtle visual tutorial on how the controls work on first launch.
2. Is it intended that you lose all your corn (and other stats) after dying? When can you use the shop?
3. It's not very clear what the objective is. Is it to collect 30 butterflies, or to reach the end of the level, or is it an infinite endurance test (but none of your stats save after death?). If it's a fixed-length level, then maybe a level progress indicator will help define that. (Example: the number of meters left, or a small player sprite that moves on a line).
4. If the game is divided on levels, then maybe the first one needs to be easier/shorter, just so the player feels like they're making progress. I couldn't reach the end after a lot of tries (if there is an end). Maybe my difficulty is because of the mouse control (it'll probably be easier on Android).
5. There is no Quit Game button, so you need to Alt+F4 to quit. A quit/pause menu during gameplay would also be nice to have.
6. There are situations where the player is in the air and a sudden action happens that can't be avoided. (Crow flying forward or a pig running from the back). It's pretty hard to test what's possible and what's not though... I think I also encountered a row of 5 chickens which I couldn't jump over, but only once. Maybe more health bonuses can even this out?
Otherwise the presentation and idea are great, and the controls are good and responsive. Will play more and give more feedback as I progress, this was my first impression.