Thepacks in some spiffing games, and it's available now. You can get your hands on Saints Row 4, Tesla Effect: A Tex Murphy Adventure, Blackguards and more.
As usual there's a series of payment levels that dictate the gaming goodies you'll receive, and as usual you can split your money between the developers and two charities;and .
Paying any price will net you Tex Murphy, Always Sometimes Monsters and three keys for Insurgency. Share those keys and you'll get a copy of Full Mojo Rampage. Pay over the average, $6.11 at the time of writing, and you'll also net yourself GRID 2, Blackguards, Euro Truck Simulator 2 and several other games that haven't yet been announced. Pay $12 or more and you’ll add madcap open world action game Saints Row 4 to your bundle.
All of those listed games are available on Steam for the PC, though from what I can tell A Tex Murphy Adventure and Blackguards are the only ones you can get on Mac. You've got twelve days to grab the Bundle.