Nice game! I really like the artstyle for the game!
It wasn't quite obvious where do we have to lead the players to, later I realised that there were yellow and blue particles as the goals. I would suggest to make the goals a little bit more obvious, maybe use colored flags? or something else to fit the underwater theme
I would also suggest adding some level bounds, otherwise the player can go outside those bounds and see those things which are not supposed to be seen (incomplete tileset and other stuff)
Overall an amazing game! Great job!