Gameshark preview: Magicka: one part Castle Crashers, one part Diablo.

"This action-RPG does have something up its sleeve though, and this could be the sleeper hit of early 2010. You and three friends play good wizards tasked with stopping the hordes of evil from freeing a bad wizard. You all have similar potential, but there is a pay off in pursuing different magical tracks. Some spells can interact with each other. You can quench fires with weak water, use strong water to push enemies into harm’s way. There is a wide variety of spell types, and it’s up to the player to discover how many of them work together.

It’s sort of like the magical combos in Bioware’s Dragon Age only this time it’s a bedrock concept behind the design. The feature notes brag of over a million possible spell combinations – a ridiculously large number that probably means there is some fudging going on in how Arrowhead defines “combination”.
The game is sort of a mix of Diablo and Castle Crashers. It’s clearly an action-RPG with different kinds of magic loot to find and experience to gain as you make your way to the boss monsters. But it’s also not very serious in its approach and often looks like a bunch of tiny wizard guys running around wreaking havoc randomly. But there is quite a bit of strategy going on here, lifting it above the beat ‘em up side-scroller that defines games like Castle Crashers.
All of a sudden, the generic world seems less generic. Arrowhead claims they are going for a Pratchett vibe in their world, treating it more sarcastically than straight up fantasy fiction, but there’s more to it than attitude. The flashing spells that destroy hordes of creature and the importance of teamwork transform a bland backstory into a chaotic romp that never degenerates into confusion."