Thanks for the link. I'm afraid YouTube says the video isn't available, though. Could be related to German copyright if there's music in the video?
Which Diamond badge would be easiest to get next (besides Technician)? I was thinking maybe doing UV Conqueror (gets me a platinum badge too) and Azrael's Scything Vaults for Scavenger Diamond.
Oh, it contains a lot of songs.. as I thought original DoomRL BGMs are a little bit boring.
I think the difficulty of getting Diamonds can be classified as:
easy - Gatekeeper, Scavenger, Longinus, UAC, Technician
normal - Strongman, Berserker, Veteran, Elite, Reaper, Marksman, Shottyman, Lightfoot, Hunter, Centurial, Daredevil
hard - Quartermaster, Masochist
ultrahard - Demonic, Eagerness, Inquisitor, Destroyer, Everyman, Arena
not 'hard' in technical means, but require dragonslayer wielding - Armorer, Heroic