I've only played two rounds in one sitting so far (got ending 2A first, then 5), but am definitely planning to return to this game in the future. Maybe in short spurts, though; it would be a shame to repeat the recurring lines so many times in one go that I stopped appreciating them.
Genuinely amazed by the fact something this complicated came out of a NaNoRenO entry - not every day you see games that took this little time with a full freaking OP video! And the whole game permeates uneasiness really well, especially thanks to stuff like parts of the background flashing in and out of sight. And that music!
The one thing I have to criticise is that it seems kind of random which parts have spoken narration; since I'm someone who tends to read pretty quickly this led several times to awkwardly cutting the narration off mid-word.