What a cute game!! The added mechanic of hitting the plane is awesome and thoughtful. I have some feed back to help you:
1) I noticed that the music might be playing positionally (at least in my headphones) to one side. Are you perhaps using the AudioStreamPlayer2D node? There is an AudioStreamPlayer node that plays it non-positionally so that the music plays stereo instead of one-sided like what I am hearing
2) I am not sure if i am confused about the controls but it would be nice to be able to move the character to the left and right. I find it a little hard to avoid the balloons just by staying in one place
Keep up the great work with the art!!! 