When the music hits in the main menu! I loved it. Art style is very fun!
My general "how-to":
1.) Select the type of spell you wish to use (Heal, Damage, Posion)
2.) Insert Prima Material to power the spell.
3.) Hit "refine" to distill it down into the magical essence.
4.) Place a bottle onto the refinement machine.
5.) Extract into bottle.
6.) Slam the enemy with the black bottle.
Tips:
1.) The more prima, the more heal / damage output generated. (Number of spells don't seem to matter)