Really, really great, as always.
But I bet you've heard that enough times, so I won't go about how innovative the 3D puzzle was, how entrancing the ambiance was, how clever the puzzles were, how pretty the graphics are, and how absolutely brilliant the game is in general. Instead, I will just report a single thing I found that could become an annoyance:
Let's say I already finished the game once, but did not have all secrets. I was lacking 2 secrets. So I go on the lookout for the last two secrets, and after a long search I end up finding one secret on, say, room 1,0, and, very excited, I use that quick teleport to the secret room, but dreadfully forget to retrieve the thingymajiger 1 that I used to get to room 1,0. I return triumphant to the secrets room and read about the new secret, but my quest is not finished yet - there is one last secret to unveil, so I set out on my quest once more to find the last secret, only to discover that I cannot teleport to 4 of the 6 possible rooms, because I do not have the thingymajiger 1 required to access those 4 rooms, I had left it in a room where the same is required to get to, Thus I am set into a situation with no option other than restar the game. Oh, woe is me.
In short, if you use the quick teleport to the secret room when you're not in room 0,0 of the root and you leave the thingymajigers on the teleporter, you will lose access to a bunch of areas, if not all.