People who don't own the PC version and yet are interested in the Mac version can apply for a beta key through this Google doc.
The beta is live now for Sanctum owners and selected test applicants
Skövde, Sweden – July 27th, 2012 – Sanctum has taken Steam by storm, winning the community's vote for last week's Community Sale. Come August 13th, Mac users will be able to get their hands on the game and experience the awesomeness that is the first FPS/tower-defense hybrid. Those who own Sanctum now will see a separate Beta version in their games list that they can download and test. For those who don't have the game yet, hopefuls can apply for a beta key here:
Sanctum is a fresh take on the tower defense genre and places the player right into the frenetic fray with tight first-person shooter gameplay mechanics. Gamers take the role as Skye, an elite soldier sent out to protect her home town, Elysion One, from hordes of mysterious alien creatures. To successfully defend your land, you must construct and upgrade a labyrinth of defensive structures and towers. When the havoc starts and the wave of baddies is unleashed, you jump right into the action with your own fully-upgradeable weapons and play a key role in the defense. Sanctum has taken the best features from FPSs and tower defense games to create something totally unique.
For more information about Sanctum, please visit http://store.steampowered.com/app/91600/. For more information about Coffee Stain Studios, please visit www.coffeestainstudios.com.