I picked it up for my fiancée and I. We played for about an hour... at first I thought it was too comical and fairly stupid, but as you get into it, it's a TON of fun.
Some of the simple spell combos are fairly useless. For example, I can hurl a fireball at things, OR I can hurl some kind of arcane ball instead! Both do virtually the same thing, just one has a burn effect. I can drop mines (they look like eggs) that heal me, or I can just heal myself.
However, some of the more complex spell combos are very rewarding and well worth the time experimenting. Experimenting with various combinations and seeing what happens is half the fun! In addition, the game has a number of minor secrets that encourage you to explore and think outside the box rather than just trudging through to the end. One of the most key features to the game is that you can do friendly fire damage (including to yourself). That means that you can't simply run around spamming spells to blow everything on the screen up, because chances are, you and your friends will be dead too.
So far, for $10, I give it a 9/10. Very fun game, and well worth the money. I haven't been to the end yet, so I can't say how long the game is. The way it's going, I hope it's at least 4-5 hours long.