acktung! 2: The Last Waltz is a map set for registered Wolfenstein. It was made by ack, and was released on February 1, 2010.
The project was made on and on-and-off basis between 2004 and 2009, as ack also contributed to many other mods during this period.
60 levels are featured, all of high quality and quite a challenge.
Being only a map set, it is playable in SDL.