Okay first of all, gameplay wise, I think this is fine. I can get behind a good maze game as much as anyone. However, I do have some personal reservations about not giving the player any real way to detect invisible walls - outside of doing what effectively becomes wall surfing to find all hidden paths.
As a mechanic? I think invisible walls are totally fine, and can work really well - I just don't really want to wall crawl the entire game to make sure I don't miss something. A hint like a subtle crack, or a glyph, or even a soft directional noise que can go a long way in helping the player out while still keeping it interesting.
As far as presentation, the game is quite pretty. Lots of nice techniques used here to give the game a polished look. And the voice over? Is that proper voiceover from someone? You love to see it.
I will say, I have a relatively mid end graphics card, so I wasn't expecting a perfect 60fps, but believe me when I say that this game suffers some pretty substantial performance issues - particularly when you look directly at the center of the map - which is where I think most of the particle effects are concentrated.
Good game! I enjoyed it - even though I failed to find all the crystals.