It was pretty fun to watch. Not much *substance* or anything but nothing in it made me cringe and a lot of it was cute. Or whatever you call adorably evil villains. I think it's my favorite episode of the season so far but I'm not absolutely certain...
It's hard to point out stuff about it because I read a bunch of people reviewing it and I feel like I'd just be copying them, so... copying them:
(a) Lots of nonlethal attacks by everypony, including the villains. Clearly, this was intended as recreation. I don't think it was really possible to lose.
(b) Rarity with superpowers is a lot more effective than Twilight Sparkle with mere superpowers instead of her usual infinite magic.
(c) Dash got... weather powers. Including the ability to summon tornadoes and lightning. Which she can *already do*. She was the most enthusiastic about the whole thing, though.
...really, everypony pretty much played along instead of struggling over 'what happened' or 'why should we care', which I thought was nice.
I also liked the completely insane, nonsensical, rambling speech the Maniac gave to her underlings.
And how everypony really does treat Spike like a comic relief sidekick except for maybe Twilight. The stated moral was that he wasn't useless, but right after stating it they all left him behind to go do stuff without him again.
So, yeah. I think I can give this one a 3 (out of 3).