That was awesome! For lack of a better description the "feel" was just fantastic. I love the creativity, it felt really refreshing. The spell casting was really surprisingly forgiving too which made it work even better.
The controls were exceptionally confusing for me. I panicked a bit trying to memorize the long tutorial texts before dismissing them, even for basic stuff that I already know like how to move, run and jump.
Some static labels on the screen that relay the non-standard game controls (Q, E, RMB, LMB) would really help as a persistent reminder after the tutorial is done.
A really fantastic entry for a first game made in Godot; it can be a hard engine to switch to without any practice so great work! I'm excited to see what you come up with next. :D