Episode 6, map 9 is the boss level of Episode 6. For some players, it can be That One Level, but for others, it's a balls-to-the-wall slug-fest where you mow down an army of Nazis and then face-off against a pretty interesting boss. If you enjoy rooms packed with a lot of guards to mow down, then this level is probably your thing.
Episode 6, map 10, the secret level of Episode 6, provides four quadrants to explore, a fun amount of guards to mow down and plenty of challenge. This is also the only map outside of Episode 2 where you can fight Mutants again note for better or worse (see Demonic Spiders below) Three of the four quadrants have an encounter with Hans Grosse who is just as strong as ever like he was in Episode 1. Besides one other level, this is the only level in the original series where you fight "Super-guards" like a more regular enemy.