There are a total of 32 different achievements in Halo: Spartan Assault which are found on four different platforms. No single version includes every achievement.
The game was originally released for Windows 8 and Windows Phone 8 devices on July 18, 2013 with a total 20 achievements worth 200 Gamerpoints on each. Five additional achievements worth 50 Gamerpoints were added with a Title Update in August 29, 2013, bringing the total to 25 achievements worth 250 Gamerpoints.[1] Two of the achievements, Tour of Duty and A for Effort, are found only on Windows.
The Xbox One version of the game was released December 23, 2013, with 30 achievements worth 1000 Gamerpoints. Seven new achievements are featured, two of which are only on Xbox One.[2] Gamerpoint values are double those found on the other platforms.
The Xbox 360 version was released January 31, 2014, with 28 achievements worth 400 Gamerpoints.[3] It features all the same achievements that are found on the Xbox One version, save for the two exclusives, The Enemy of my Friend and Immune.
Players with the proper hardware can purchase Spartan Assault for each of the four platforms, and potentially unlock many of the achievements 4 times. Playing on all four platforms will allow the player to unlock a total of 108 achievements worth 1900 Gamerpoints.
List
Trivia
Unlike achievements in every other Halo game, Spartan Assault achievements appear on four different platforms. This results in a duplication of achievements; players can unlock the achievements once on a Windows 8 device as well as on a Windows Phone 8 device, the Xbox One and the Xbox 360. These achievements also appear multiple times on Halo Waypoint. Although this can allow players to boost their gamerscore by unlocking the same achievements up to four times, it also creates the unfortunate circumstance wherein players looking to unlock every Halo achievement and reach the maximum Career milestone must purchase and play Spartan Assault on all four platforms (and for some, purchase the platforms themselves).