You play as a wizard who has taken it upon himself to defeat a bunch of people wearing black hats whilst being shot at. You have many spells at your disposal, unlocked from kind-of-rare enemy drops. But your bread and butter will be the Fireball Spell:

But you also have the Black Hole spell, the Freezing Spell, the Clockblocker and six more. Simply murder the people/snowmen in black hats until you are defeated. Use the final spell to get a sense of victory.

Play it here: Intense Wizardry.