These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: Between Day Z players and ARMA II players. A number of Day Z players find the core game to be a boring, obtuse game that only Armchair Military types would even want to bother playing. Meanwhile, ARMA II players get annoyed by the fact that Day Z and mods like it are going against the core game's strong teamwork-based mechanics and military simulation theme.
Just Here for Godzilla: DayZ has done this to the original ARMA II that the Steam store page for the basic Arma 2 game has a service warning (usually reserved for serious regional compatibility issues or the like) informing the user that the mod requires the game's expansion pack and providing a link to a suitable discount bundle.
Paranoia Fuel: The other survivors. Even if you team up and make friends with someone, there is nothing stopping them from stabbing you in the back later (or you from doing the same for that matter). A writer at The Escapist has even commented that the primary source of tension and horror in DayZ is not the zombies, but the other players.
This will often result in the most horrifying noise being not the groan or barking of a zombie, but distant gunshots or the roar of an engine.