Video game spellcasting tends to be unlocked slowly and carefully so that you can wield its devastating power without killing your friends.
This is not what happens in Magicka.
My brother describes it as "unlimited destructive power, poor impulse control." I think it fits pretty well. If you ever wanted to play as Black Mage from 8-bit theater, this is the game for you. Mana? Pfft, these wizards use magic as much as they want. Friendly fire protection? Bah, it was their fault for not casting a shield spell soon enough. Or to put it another way: the resurrection spell is quick and easy to cast for a reason!
Really, just look skip to 12:30 here:
http://www.youtube.com/watch?v=wZHhwUK8aj8&feature=relatedThat's all you need to know about Magicka.
Obviously more fun in multiplayer.