The ending (spoilers)
So he became a walrus?
I wanted to see a little bit what happened when they found him instead of cutting right to where he was still a walrus.
I think they were implying there was nothing they could do to save him, so they let him live out his life as a walrus. But when they did a flashback to why his girlfriend cries and that her Grandma said it's what separates humans from animals, we see him cry and it implies that he is still human inside and he's trapped.
I feel that ending is more depressing because he's trapped as a human living in a walrus body as opposed to having completely lost his mind, which may have been the more sane goal for him.
I wish they showed who was taking care of him at least or how they set up that little sanctuary for him.