The games in the base pack for any price include:
* Natural Selection 2 * Sanctum 2 * Magicka, including Dungeons and Daemons and Vietnam DLC.
Paying over the average (currently $4.21 USD) adds:
* Sanctum Collection, including two map packs and the Sanctum official soundtrack * Orcs Must Die! GOTY Edition, including all DLC * Orcs Must Die 2 Complete, including Orcs Must Die 2 - Are We There Yeti?, Orcs Must Die! 2 - Family Ties Booster Pack and Orcs Must Die! 2 - Fire and Water Booster Pack * Cities in Motion 2 * Garry's Mod * Serious Sam 3: BFE
As usual, the Humble Bundle can be picked up at the official site here.