I had a good time with this. Smart decision to have very simple art and spend the time on physics and gameplay mechanics. The sound adds a ton to the atmosphere.
I wasn't able to reach the final island... my bote just kept tipping over. Even when I moved all the way to the opposite side, at slow speed... it still tipped! That felt unfair.
I feel like there are 3 main ideas explored with this: navigating, balancing and steering. Navigating and balancing are ramped up as you advance through the islands. Steering remains pretty constant (except for dodging the pre-pyramid obstacles).
I didn't care much for the balancing mechanic. I really liked seeing my bote react to my weight as I moved around ... but I didn't like getting tipped over. It felt too opaque as a challenge.
Personally I loved the navigating and steering. There's a real sense of magic when having a new destination and working out how to navigate there. If you kept ramping that up I would have loved to keep playing. Even with very basic art I could feel that sense of exploration evoking something in me. The steering was fun too, I would have enjoyed some dangerous obstacles along the way.