Nice Idea ! However, I think the difficulty is way to high, probably due to randomness (couldn't get past lvl2). Maybe making the player having more impact over the spells casted could help, cause it's actually current to loose because you get only links or health. Also, it could interesting to make the current spell bigger, instead of having a line of ?, so it's more clear what's going on.
Again, there is many good idea in this game ! Loved the link mechanic, and the game concept is solid too. Good job !