While two of Sublevel Zero's primary features (permadeath and procedural generation) tend to do the game a disservice, its moment-to-moment gameplay stands as something unique enough in the current FPS landscape that warrants at least a look. However, the incongruous nature of permadeath and procedural generation in the game doesn't necessarily make Sublevel Zero a game worth returning to for very long.
An interesting mechanical conceit that does little to build on itself.
Returning players need not pay any mind to the Deathinitive Edition, especially those that already consumed its additional add-on content. That said, those that have yet to step into the shoes of a Horseman of the Apocalypse and are seeking a solid action-adventure RPG need only to knock on Death's door.