Playing through it with some IRL friends, really fun!
But unless everyone in the "team" is pretty good at it and play somewhat safe it's reaaally difficult without the infinite continues crutch :D
It's fun but once you finished the game with the four classes there's not much left to do. Unless people make some very good quality custom maps with the editor.
AFAIK, there will be another official episode (free), there are new classes planned for an update (rogue and priest iirc) and there's already lots of fan-made stuff popping up.
And multiplayer with randoms can be fun! Some games you have a +forward guy throwing away all your lives in second floor, but I've played a game where we've slain the maggot queen without any crutches (I bet they went further but I had to leave, too bad you can't play each section separately in multiplayer).
So thief class from the previous update was dreadful (using coins to shoot, I've tried on hard and never bought any upgrades).
But this priest class that came out today is really easy in the beginning. I wonder what his other skills will be! (why doesn't this game have documentation? grrrr)