I really like this game. 5/5
I've completed most of the levels and found two issues with the level selection.
1: If I've played on regular Levels 61-90, and switches to Challenge Levels, Relaxing; the interface will display no levels to play because it's still displaying 61-90 (and there aren't that many levels on Relaxing).
2: When I play the Challenge Levels, and complete say level 9, and click next level to level 10, I will get 'A new clue type' as if I was playing the regular levels, and then be sent back to the regular level 10. Quite annoying.
I kinda liked the game. It was a bit irritating though, that I never knew if I was finished in a room, or if there were more things to do in it...
Love the setting though! Very 'Neverwhere' =)