I'm not sure if it's still free on PS+, but I played it through PS+ myself, and it's an okay game. If you got 3 friends who own PS3's that you play online with, it'd be a lot of fun I'd imagine. But for me, I played through the vast majority on my own, and a little bit of the game with a few randoms.
The game is seriously flawed in so many ways. Cut-scenes can be skipped offline, but not online. Enjoy that. Remember that this is developed by the 'new Insomniac team', without question they squandered an opportunity to make a great game.