Nice classy map. Like mentioned here before, for me playing on hard was not a real challenge. I was close to run out of ammo, but it was just enough to easily finish the map.
I found 3/6 Secrets on my first and only run that took me around 15 Minutes. I found another 2 secrets, after finishing the map just on my secret hunting run. I could not find the last secret and wonder why I didn't archive 100% Kills, but just 90%. Seems I didn't find a hidden path or kind, that spawn in the rest of the monsters.