I tried a bunch of times and I just couldn't fish a single thing out of the ocean, but it's a really charming idea! The acceleration is too low to be able to dodge octopi as soon as they decide to approach you, but there's also no apparent cap on acceleration so you can get grooving really fast! The best I could do was get going at a good speed, drop my hook while the boat was slowing down, and repeat until it was at a proper height for chests.
There's just a couple issues with game boy limitations. The graphics scale with the changing window size, but other than a couple bugs I experienced, the default window size has the right scaling so I won't mark it down for that. However, the main menu does use mouse input, which is not a valid game boy control :)
Great job nevertheless!