I'm sitting beside someone playing The Division. It's a computer game set in NYC just after Christmas - a Christmas wherein someone infected dollar bills with a genetically engineered virus. He put the bills in circulation and the virus wiped out a broad swath of the population. The premise of the game is that it's January. The player is an agent in a clandestine organization called The Division. The player is activated as a means of reclaiming the city and lending aid to the remaining survivors.
Amazing world building. The story tellers/game developers seriously thought through the threats, the challenges, and the ways people would react to the disaster. They really considered how long it would take for essential services to break down - how long it would take official government agencies to sweep in and cordon off the city before they, too, started dying.
But there are some serious gaps, if not in world building, then in logic. All of the firetrucks and police cars have their lights on and flashing. The cars are abandoned, their hoods crumbled, but their batteries are still good, by God! However. People have been dead for so long that all the dogs in the city have become feral. The single biggest miss by the dev team? The dogs aren't roving in packs.
Do you know how long it takes dogs to revert to feral? It's a researchable parameter. Not to mention that anyone who's watched a single National Geographic episode knows that dogs are social animals. They require a pack. In our homes, the accept their human families as pack substitutes. Were that family suddenly taken away and a dog had to fend for itself, it would have to have another pack. The dog would automatically seek other humans and ask for help. If that didn't work and the dog didn't simply starve, it would, for its own psychological survival, have to join a pack of other free-roaming dogs.
It seems like a little thing, doesn't it? But it's indicative, to me, of some lazy world building within the game. Someone simply went, "Cool element! Feral dogs!" But no one bothered to ask a simple question. "Hey. If the dogs went wild, why are the crumpled cop cars still flashing red and blue? I mean their car batteries died in the first 72 hours, right?"
It's proof that misses don't have to be great big hairy things. It's the little things that build up over time and really start to bug people. Ask Walking Dead fans whose visages harden and whose lips thin ever so slightly whenever the Rick and the group drive past an obviously cultivated field or a mowed lawn 2 years after the zombie apocalypse. (Also, why do the cars still start? Have you ever had gasoline varnish in an engine after a single season??)
World building is very much akin to the cultural iceberg - we only see the tiny bit above the surface, but there's an entire huge structure underpinning what we see. That invisible structure requires deep thinking if you're going to be creating it. It is where the 'why' comes from for your world. If the 'why' is firmly in place, a writer is less likely to miss the kinds of world building elements that'll get books tossed across the room.
I, personally, have a pet peeve about time travel stories. I have yet to see a movie with time travel as an element that didn't shoot itself right the timeline. (Meaning the story creates an Asimov Paradox even after Isaac Asimov described the paradox so writers could avoid it.)
What world building/consistency misses rub your fur the wrong way?