First off, the things I didn't like so much.
The biggest bummer for me was losing the run power up once I got onto the mountain. That area was rather large and based on exploration, and I would have enjoyed the level a million times more if I could just run through it to find the keys. I actually ended up using the cheat to warp across screens I had already traveled across. Another thing I didn't like so much was the no climbing walls. I read earlier on this topic that you meant the one-tile-thick columns to be unclimbable, but that wasn't so easy to understand right away. I think that if you had added another type of visual cue (such as making the columns a slightly different color, or making visible ice on the sides), it would have been easier to understand what was climbable and what wasn't. The umbrella room code was also annoying to figure out, since I had to recall a hint I had heard twenty minutes earlier in a cutscene, all while an enemy was chasing me. Some additional hints right before the puzzle would have been a welcome addition, along with the removal of the enemy. Finally, the cutscenes were all awesome, and I enjoyed hearing voice acting from the forum members, but I would have enjoyed it if they were just a little bit shorter. The scenes ran a little long for my tastes, but that's just a personal preference.
Now that that's all out of the way, let's talk about the awesome stuff!
Playing the game in KS Advanced felt great, especially with the self-moving cutscenes and red flash of death. The dark tunnel with light around Juni and the one way jump platforms were also cool, and the secret area showcasing different KSA features was delightfully trippy. The voice acting was all interesting to hear (although a few characters were kinda quiet), and the story looks like it's going to be great. My favorite thing by far, though, was the music. It fit in very well and sounded beautiful.