Borderlands 2 arrived on the Mac late last year, but unfortunately the publisher, Aspyr Media, wasn't able to get the multiplayer working in time for the release. Today the company has released a patch that enables multiplayer co-op through Game Center, along with leaderboards and achievements.
Aspyr has also made five different content packs available through in-app purchase, so you can pick up new items, new levels and the Mechromancer class as well. To celebrate the game's update, Aspyr has put the title on sale at 50 percent off for a limited time, so you can grab it for just US$29.99 right now. It's a shame this content wasn't available at launch, but better late than never, and having the game available at such a low price puts us in a pretty forgiving mood anyway.