The set was notoriously difficult due to the heavy presence of enemies, mainly on skill 1, and as such, two separate downloads became available; a standard and a hardcore version. The standard version was slightly easier and was released on November 11, 2010.
Though the title indicates otherwise, sprites and bosses were added from Wolfenstein 3D; these include the domestic sprites (sink, stove etc.) and all of the bosses and the Hitler ghost, plus the Pac-Man ghosts.
Mapping was dense and crowded, and as has been mentioned, quite difficult. The static object and enemy limit had been raised and was very much taken advantage of.
Coding changes were made by WLHack, and ack contributed level 21.