I wouldn't call this game fun, but it's really very good. Despite how tedious it is (especially if you decide to go for all 5 endings like I did) it's got a lot gratifying moments, and plenty for the player to wonder at. I say "wonder" because it really doesn't give you any answers, only mysterious/intriguing details.
Ending 1 was the most fun for me, since the game's affordances lined up with my desires. In other words, the game actually let me do everything I wanted to do; if I wanted to stop and check this thing out, the game let me do it, and actually gave me dialogue for it.
That might have just been luck, since there were several moments on subsequent playthroughs where I felt let down when I couldn't do something I wanted to. For example, I wanted to follow the animal tracks that lead away from the first cabin, but you can't walk off that side of the screen.
SPOILERS BELOW
The chase with the crows towards the end felt really intense in a good way; my vision tunneled and I was entirely focused on pressing the arrow keys as fast as I could without messing up, just hoping that I could make it to the end before I died.
The Forgotten was by far the most satisfying ending to get. I audibly gasped when I was actually able to enter the path to the graveyard after remembering where it was from my previous The Found run. I had to do another The Found run in order to write down the directions through the maze with a pencil and paper. I was so worried about dying to the crows and having to do it all over again. The fact that they never appeared was spookier than anything else in the game in my opinion, and I'm still wondering if there's lore behind that. (Sidenote: it seems strange to me that The Forgotten is ending 4 rather than ending 5, since it's clearly the most complex ending to get.)