I see lots of potential here. The idea is good and the game is pretty cute. I don't know if there is something after the third boss cause after I defeated it it just vanished dropping nothing and I couldn't get up again.
My first impression wasn't good, that's my fault cause I skiped the first boss on my first playthrough, then it disappeared getting me stuck. On the second playthrough I've faced the boss and the game's true value opened up and I had a lot of fun.
Had some difficulties with the controllers, first cause the mapping wasn't stated nowhere, but after mashing some keys i found it was intuitive enough to not be so much of a problem, second cause I felt it missed some fine-tuning like if you want the jetpack to take the player up it should do it more promptly, it felt like I was always barely making it to the ledge, or when you hit and enemy at such close distance they should stall or be pushed back or else you'll end up being punished for landing a hit by taking damage cause the enemy didn't stop.
The level design was interesting, it made me engage and want to explore the whole world, and felt rewarded for that with the extra life in form of the melon pieces. But... It was very linear which hurts a bit the concept of being a metroidvania.
To finish, some parts of the art where a bit blurry while some were very crisp which caused some inconsistencies with the style you were going, and in some part in the middle of the playthrough the music stopped suddenly and I don't know why. Missed some sound effects, but I forgot to put them in my game too lol.
Overall I think the idea has a lot of potential and would be something I'd buy on steam if well executed.
Congrats on your submission and good luck!