I am not into MOBAs, but I have had a blast every time I've played Magicka: Wizard Wars. Probably because you could murder sheep into a blood cloud and people didn't yell obscenities at me. And because Magicka is fun and surprisingly suited to the genre.
And even if you don't like MOBAs, the straight up Duel Mode is great. Plus, it's free and the above trailer nails the game's welcomed, humorous tone. Like pressing the confetti button while you spectate duels.