Played the first 2 levels of your game : a lot ofgood work and ideas !
The controls still have a lot of room for improvement (i was playing with a dual-stick controller) : they work, but you sometime need 3 fingers to imput an answers (the two sticks + confirm) wich can be tricky.
Maybe you can solve all of this with mouse-control (i mean : everything is pretty visual : with a mouse i could point the right answer efficiently, and even draw better than with dual sticks). Also, mouses-control are great to move in a isometric-3d environnement (right click/left click give a lot of options).
I agree with Kattywampus on all of the sound-feedback.
One of the thing i have find the more helping in the game was when another caracter tell me a trick (like think of "KI" as a "key"). Those mnemotecnik tricks where all given "in bulk" by a text-box at the start of the 2nd level, but maybe it would have been more efficient if i "discovered them" one by one by talking to someone in the forest (like, in a mostly safe-zone at the start of the level, or in one of the corridors). Maybe "finding" those PNJs once in the forest making them accesible latter in the start-village ? (More Pnj's diversity could be great (other "persons" not only faeries).
Only visual complaint : the particles on the sword. Nice 5 minutes, then too much present. Overall visuals works fine : a little more diveristy and they'll be plenty of thing to watch without needing a permanent-sparkly effect : ).
Anyway : will follow your work, core game is working nice, time content and level-design can only improve that.