Wolfenstein: Enigma is a remake of Wolfenstein 3D on the GZDoom engine. It retells the entire classic trilogy with inspirations from not only from other Wolfenstein games in the series such as Return to Castle Wolfenstein, Wolfenstein 2009 (Raven Software) and Rise of the Triad. Various other Wolfenstein mods are inspired for this mod, especially Blade of Agony.
While all chapters from concepts wise are not finalized, it brings some ideas on what the final release will be like. Of course, Spear of Destiny and it's expansions by FormGen will be included but with an exception of how terrible Return to Danger and Ultimate Challenge by FormGen Corporation were, I'd realistically re-create only Return to Danger instead.