Bucked up, started hardcore mode with help of maps. Surprisingly the scariest level, Into the Abyss, only took me one try. Mostly due to a miracle, because I ended up crossing the long upstairs bridge twice to look for my final gas canister and there were no double ganks.
Genesis took me three thries and a run where I found each page's location beforehand.
(Total playtime: 7h 10m)
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Then did the miscellaneous achievements remaining, speedruns and fire hitless.
(Total playtime: 8h 21m)

Played the game on easy. Very tense ambient, but there is no way I was going to find everything without a guide.
Took my time to familiarize with each map and get collectibles.
Then started normal.