I've been playing since the beta version.
And the other day, I finally cleared the difficulty level "EXTREME"!
At the highest difficulty level, it takes a lot of luck and retries.
There was also an extra dungeon, and this was a map with more of a puzzle element. It seems like it's for people who have a solid understanding of how to use magic.
As far as normal play goes, there are relay points where you can use your magic to advance through the game, and if you want to try out the other modes, it can be a challenging game to break through by trial and error.
Nice work! :)