Interesting game concept, but would like it if the separation between the "training level"s, where you're introducing a rune, and the "recall levels" where we have to remember what they mean was a bit more obvious, and maybe if there was some sort of plot framing device?
Mechanically, it would be kind of nice if once a stroke was detected, the game "locked it in", and it could be erased if that went wrong (e.g., the long base line for the rune, or the "flags" from the k-series runes). Right now, it's hard to know if, when I'm not getting a level, it's because I've forgotten the rune shape, or if the engine just isn't detecting my strokes correctly.