There's certainly been a "loop" trend in horror games since PT hit the scene (which is impressive, considering how long ago that demo dropped!), and I'm here for it and all about it!
This really is a curio, and it had me throwing out theories all over the place! The best thing about these kind of games is that you can make your own mind up about what's going on, I've always liked that aspect of some games. Don't get me wrong, sometimes I like a nice firm obvious explanation, but every now and again you just kind of want to let your mind go nuts and come up with its own crazy explanations!
So, there's not a massive amount of gameplay in this little experience, but the atmosphere is great, the setting is nice and claustrophobic and the ending(s) are weird and wonderful!
Highly recommend giving this a quick playthrough if you have 10 minutes to spare.