Thank you for your feedback!
I didn't expect anyone would play that far :D My idea was to give it a little touch of: "Oh, I upgrade this, but now I'm struggling with the other part. After upgrading this, something different is lacking."
The fact that the upgrades won't help you very much to dive deeper is due to the fact that I ran out of time to do a good balancing.
Maybe you also missed content like dangerous mines and an angry fish that tries to smash you against walls. There is also something missing as a benefit for fully upgrading your boat... Like, why should you play after everything is maxed out?
Thanks for giving it a try! Let's see what I can do after the jam to make it comfortable and replayable :)