I was also very impressed by this game. Tom's GMing (Keeping?) style is spot-on: he populated his game with memorable NPCs, a setting rife with vivid imagery, and a villain that made me want to scream and hide under the bed.
CAUTION: Ahead be spoilers.
I loved Grunefeld especially for the antipodal aspects of humanity and inhumanity united in his character--he listens to Mozart while he dines on human flesh, for God's sake! Kohl and Schuller turned out to be total badasses, one because he pulled himself back from the brink of insanity, and the other because he competently navigated his way through the scenario while his squad mates fumbled at every turn (thanks to Tom's lucky die rolls).
The setting was also a gem for a CoC / survival horror game--isolated, buffeted by severe weather, and somehow claustrophobic even in its open spaces. Tom dreamed up some wonderful images for the game as well. The two that come most readily to mind are the defrosting portrait of Hitler in the colonel's office and the sentry frozen to his machine gun in the guard tower. Stuff like that really puts you into the world as a player, and Tom sprinkled it in like a pro.
Perhaps the best part of the game was the villain, a presence from another place slowly changing the Nazi complex into its home away from home. The monster that chased them down a the end, the dead colonel sitting up and speaking in the bath tub where he committed suicide, and the radio that channeled the voices of the Nazis trapped in Area G were flat out awesome devices, each of which added to the inhuman power and cunning manipulations of the mysterious unseen enemy.
I hope this scenario is published at some point, because I would love to read it and run it for a group of my friends. I think they'd really get a kick out of it.