I strongly suspect that this developer has both played and enjoyed Pikmin and Wind Waker. A very short game, and not particularly challenging. Smushi's key draw is simply how pleasantly the environs and soundtrack create a calming world to traverse for an afternoon.
I always enjoy a tastefully implemented adaptive OST, though I do wish the background music for traversing the final zone didn't fade out if you're swimming slowly. I wish that one went full blast regardless.

Capybara? Capybara!