Has anyone played it yet? For some reason the trial isn't available yet but the full game is. I'm pretty sure I'll buy it but still want to try it out first.

Yeah, it's a bit odd that there's no trial. I was under the impression that having a trial was an XBLA mandate.

As someone with approximately zero friends to play co-op games with, I'm curious if this game is even playable solo. Everything that I've seen has presented this as a solely multiplayer game.

I was worried about the no trial thing too, apparently it is being looked into

From Major Nelson's Twitter:

"Hmm...no trial is appearing for "BattleBlock Theater" and there should be one. Investigating now."

@chaser324: Nah, I think there is a fully featured solo game in there, as well as tons of other things. They have even been talking about "story" and cutscenes in a few interviews. I´m sure you´ll get plenty of SP content.

I´m not gonna buy it before seeing a Quicklook or playing the trial. Stop screwing things up, Microsoft!

The review I've read said that

The game’s Story mode can be enjoyed solo, but get ready for a whole new experience if you play it locally or online with a buddy. The stages in co-op mode have been tailored for two players and require teamwork to complete.

Also it sucks not having anyone to play co-op games with. I've also got zero people to play with. I'm still missing the co-op Halo 4 campaign achievements because I just have no one to play it with. I generally miss out on a lot of co-op achievements and games because of this. It sucks.