One of the best I've played so far, I love this game! The art of the all the bosses and the charatcer itself is so good and cute. And I love the reward of endless bubbles at the end haha! The limitation theme of needed air bubbles is really clever, good job! ;)
My only gripe is that maybe it'd be better if you could have more than one bullet on screen at a given time. I realised after a while that new ones only spawn once your bullet is gone, so staying as close to the boss as possible and spamming shoot makes the game really easy lol still gave it 5 stars across the board though, that's just my suggestion :)