It's that time of month for some updates of free games from Xbox Game Pass for December. Coming up next month, subscribers to Game Pass Gold and Game Pass Ultimate will have access to The Escapists 2 and Tropico 5. And through Backward Compatibility on Xbox 360, Robot Entertainment's tower defense strategy simulator Orcs Must Die, and the 2D action adventure game Insanely Twisted Shadow Planet.

The Escapists 2 (Available December 1 to 31): From the tundra to the desert, join up with three of your friends to form the ultimate crew and engineer the wildest escapes from some of the toughest prisons in the world. Live by the rules, attend roll call, and follow strict routines, all while secretly planning and executing your bid for freedom!

Tropico 5 - The Penultimate Edition (Available December 15 to January 16): In this Penultimate Edition, including The Big Cheese and Hostile Takeover add-ons, expand the reign of your dynasty from the early colonial period to beyond the 21st Century. Build your city’s infrastructure, plan your trading routes, and utilize new technologies, in the fifth installment of the fan favorite city-building series.

Orcs Must Die! (Available December 1 to December 15): As a powerful War Mage, defend twenty-four fortresses from a mob of beastly enemies, using all manner of weapons and traps at your disposal. No matter how you get it done, you’ll have a blast destroying rampaging monsters in this fantasy, action-strategy game.

Insanely Twisted Shadow Planet (Available December 16 to December 31): Explore unique environments in the 2D action-adventure game, Insanely Twisted Shadow Planet. Make your way to the center of the mysterious Shadow Planet, all while solving complex puzzles and battling bizarre creatures, as you fight to save your home world.