A masterclass of tutorialization, mastefully executed. Great to see more Gamemaker devs too.
Excellent puzzle design all around, cryptic enough yet self explanatory, exactly what's needed to make the player feels smarted than what they actually are, absolutely great. Your soundtrack is pleasing while discreet enough to not disturb gameplay, great choice.
Extremely solid entrey, my one problem with it is that I failed to understand your implementation of the theme.