Thank you so much! I'm really glad you enjoyed it! Especially the sailing, since it was one of the mechanics I wasn't sure would work that well haha.
About the shader compilation, I have a list of all the objects, materials, and effects used in the game. During the loading screen, I instantiate them in front of a camera on a separate rendering layer, so they're invisible to the player but still get rendered and cached by the GPU.
The progress bar is basically tied to how many resources have been processed, so it's not an actual shader compilation percentage. That's probably why it sometimes gets stuck around 60–90%, since some resources take much longer than others.
I also recently found a bug in my loading system! I was unnecessarily waiting one frame between each material, so it was only processing one material per frame. I changed it to process 8 materials per frame, and now loading is MUCH faster!
GPU particles are still a problem, though. I haven't figured out how to properly prewarm them in web builds yet, so they can still cause some stuttering when they first appear.
And seriously, thank you for such kind words! I really loved your boat too! Let me share a little tip: games don't always need to feel realistic, they need to feel comfortable to play! :3