Hi there, nice way to start jamming, welcome aboard! ;) I really liked your graphics and, has you mentioned, missed the music background, since this fast pacing platforms kinda require that. I did not find the time to add sounds to my game as well... :P
I felt like the camera was up too close, so it had to move a lot only to keep the girl on the screen for a single jump. I have to confess that it took me a while to get used to the fast moves with a view so up close. The idea of being able to shoot only when the flower is in the air is good, but as @petturtle mentioned, if the flower was bigger, that would help a lot. And again, if the player was able to see the flower up in the air while shooting enemies it would be fair. If it was meant to be this difficult, than maybe there should be some sort of progression, cuz the player will just get frustrated and give up, so he will not enjoy all the levels you planned.
Another thing, since there is a health bar in the right, I felt bad for dying so quickly when touching the enemie. That bar went straight to zero and game over. By the third time I gave up because I had to do all over again. Maybe some checkpoints along the way, idk...
Well, congrats and keep quality games coming! ;)