Even though it isn't chiptune, I can somehow still tell that it's you who wrote it. Your style transcends genres, it seems.
Blarg. I wish I hadn't read the notes now, because biology. Now, I can't get the image of a pulsating blob of tissue out of my head whenever you get to the sidechainy bits. That background gulping noise (?) that becomes slightly more prominent at 3:45 doesn't help either. :P At least I can see an image, so your atmosphere is definitely image-provoking, which isn't how I normally think.
Speaking of the word 'atmosphere', I've always used it as a synonym for 'mood' rather than a type of mood. I guess I've been using it wrong. I'd describe this as having an airy or breathy atmosphere, but the term 'atmospheric' describes it pretty well.
I actually think this song isn't too long. I mean, sure, it's repetitive and lulling, but it's certainly a welcome change from your chiptune. It's in a similar vein to your other music, but it's different enough to keep me interested while still preserving that johnfn quality that you've basically mastered. I couldn't tell you what it is, but I can tell it's there.
I don't really know why I'm leaving this review when you've done all your own critiquing for yourself. Come on, leave some for the rest of us! I'm docking half a star because of, as you said, the mood. Yeah, I appreciate it, but I think you've done enough work with calm and "atmospheric". Try something people can't really imagine you doing, like a rock song! :D That'll be the day...
That ending. It's like you have an obligation to piss at least one person off with each of your songs' endings or something. Fade-outs, incompleteness... It's an interesting quirk, so I don't really mind it, but it's going to garner some opprobrium. Watch out.
It's great to hear you use new instruments! Try new things! Be inventive! Great work.