The pictures on the wall of Hell are real and historical photos that have been published in newspapers and websites. Google has not set a warning for these images either.
Viewing post in A Visit to Hell : First Person comments
Don't even remember exactly, but the game itself is quite ok, although thematic, but there are pictures in frames on the walls which contain pretty gruesome and intense pictures of events that actually happened, but still, it felt 'out of place' for me, not sure if WW2 imagery was in there, but themes are related to wars and the brutal things happening during wars.
Pretty much all the games of Hammergames have a lot of propaganda in them, which for me devaluates the games themselves.