I have to say that I'm basically agreeing with booellean about the game and the points which could be improved. However, I have some additional points:
1. I know that you put a lot of work in layouting the levels, but for me both levels felt a little too long. Breaking them down may be too much work now, but havnig more levels would benefit the jam theme with "one more time".
2. I think the hit detection on the enemies could be improved. So you not only kill the enemies directly from to but also from the top left and top right. I found myself getting damage way too often because I was just a little bit too low for the head detection.
3. The sprites for the pig birds are just scaled up. Maybe invest some time and redraw them with the same resolution.
Other than that really solid game. Good job for your first game jam. Looking forwart to seeing the final result.