Really nice style! I loved the ocean water.
I found the music volume to a bit too low. Had to crank up the volume to listen, but it is a very calm cool song.
Took me a while to understand what did the drawings on each box meant.
I didn't understand why some boxes would get bigger or small, but it was fun trying to scale my boat and shooting those pesky seagulls.
Managed to last 2:25, but a ship just 4 meters big.
Maybe you could also get some gems sometimes, it gets hard after a couple minutes with pretty much only seagulls spawning.
Congratulations on making a stylish fun game!