This is by far the best PVP game I've ever played. And I do mean "ever". Upon first glances it might seem to one that this is a MOBA. It definitely has those characteristics, but I'd go so far as to classify this is an "unconventional" fighting game.
Like a fighting game, you have to know and master your character's abilities--attacks, defenses, counters, etc. Like the original Magicka, you are using 8 keys (QWERASDF) to create DOZENS of spells on the fly, although in this one there is only three slots for each element. Also similar to a fighting game is the fact that there is telegraphing. Each spell queued up is visible to your opponent for a split secdon, so he/she will be able to react accordingly. This leads to extremely fast gameplay that requires some really good reflexes.
The downside is that this game is has a VERY high learning curve to anyone who never played the original Magicka. You will need to devote as much time and effort to learning the spells and casting them (which just means you have to learn to type FAST) as you would any "conventional" fighting game. This has turned off a lot of new players (just look at the steamcharts) because they either become frustrated or just don't have the interest in devoting that much time to a game.
HOWEVER, to anyone who has taken the time to learn this game throughout, it becomes very apparent that the developers of this game are GENIUSES and that this really is one of the best most action packed 100% skill based PVP games that he/she has ever played.