A friend and I played this as a DM-less game over a couple of hours, and it was a blast.
I do think it's probably better with some advanced planning, as the wacky premise made collaborative story telling a little harder than other games I've done. The art is great, the non-wizard options are hilarious (we were each different familiars in trench coats who didn't know the other wasn't a wizard), and the magic options allow for creativity while guiding players.
Would recommend!