Thank you!!
The whale was just meant to be in the game... not part of a puzzle or anything... I added a mesh collider to it and it didn't work so I thought I'd just ignore it and move onto something else.
The central problem with the game is the island itself. It was difficult to create enough visual keys to show the player where they are and where they have been. That's an inherent difficulty with using a 1-bit color palette. The solution was probably just to make the island a lot smaller, but I didn't have time.