A new batch of games has landed on Steam for Mac. While there are several new single-player titles available, it's the new multiplayer titles that are particularly noteworthy. The reason: Multiplayer is compatible across both Mac and PC platforms. Leading the cross-platform charge is cooperative zombie murder sim Killing Floor. Two other cross-platform titles now available include Madballs in Babo: Invasion and Altitude, a 2D aerial dogfighting game.

To mark the occasion all three games are on sale, with Killing Floor priced at $13.99 (33 percent off) and both Altitude and Madballs available for $4.99 each. Plus, Altitude will be free to play this weekend. Incidentally, these sales apply to the PC versions as well.

Find a full list of this week's new Mac games after the break.