Dear Esther: completed!

I started this a few times but never devoted enough time to see it through - my previous work computer stuttered horribly with it as well.  I tried running it on my seven-year-old iMac and it works wonderfully, even at high resolutions.  Huzzah.

And I played through the whole game in one sitting - I'm not sure, in fact, if there is a save mechanism.  Or, indeed, a game - it is very much an interactive novel, with the story told by narration over the top of the exploration.  Sure, there are some hints to find across the island and some of the things you see constantly make you question whether this is a hallucination or dream, but you can't influence the story in any way, or die; you can only trigger the next part of the story by walking far enough.

It's a complex story as well, and by the end I think I'd figured out a decent interpretation of it.  I believe that your character is lying in a coma, desperate to tell Esther about the circumstances of the car crash which you were both involved in.  The island doesn't exist other than as a construct of your mind - there being no way off indicates the way you are trapped without hope of recovery.  Quite bleak for a game, but continuing the theme of To the Moon nicely.