First off, I searched for "Magicka" before posting this topic, and saw that there was already a thread for the game in this forum. But it was a really old topic and had a bit of a negative vibe to it, so I decided to start a new one instead.
For those of you who haven't heard of it, Magicka is an action game where you play one of up to four wizards who can combine elements to create spells, and use those spells to fight various monsters. It may not sound like anything new, but the magic system in this game is truly innovative.
I can't describe it very well myself, so I'll just give you a link to a video called "WTF is Magicka?" that shows you the first part of the game and explains the magic system. I recommend skipping past the prologue and only watching the gameplay parts of the video.http://www.youtube.com/watch?v=g_XP9OBWGKo
And personally, this is the most entertaining game I've seen this year, so far. Not only for the truly unique magic system, but also for its great sense of humor. It made me laugh out loud many times while I was playing the adventure mode, and that doesn't happen to me often. There are nerdy references everywhere, and I loved it.
Also, you definitely should play it in cooperative multiplayer. It's a lot more fun when you have a few friends with you, especially considering the friendly fire aspect. You can and will kill your allies and even yourself with your spells, whether by accident or intentionally, and those moments are generally the funniest ones.