During certain events, the game would apply cosmetic changes to game. Well, it's hard to explain, but examples should clear everything up.
So, on 24.12-31.12(or even entire December) the game would render a santa hat on every player, every monster, and on everything (even trees).
At April 20th (Weed Smoking Day), wheat would be replaced with weed. (I do not smoke weed, nor support that kind of behavior. I do find that celebration to be pretty comical, and thus, on that certain day, it would be acceptable).
On Halloween, changing things to look more spooky, maybe dressing up monsters into costumes (not something special, so it's more funny, and you can still recognise the original monster, for example bats with white cushion being ghosts).
There are many celebrations, like Valentines, Easter, Summer, so it might turn out to be pretty good.
How can this work? Well, it could be the game checking server date, or client date (so if you change your date to Christmas, you would get hats).
So, on 24.12-31.12(or even entire December) the game would render a santa hat on every player, every monster, and on everything (even trees).
At April 20th (Weed Smoking Day), wheat would be replaced with weed. (I do not smoke weed, nor support that kind of behavior. I do find that celebration to be pretty comical, and thus, on that certain day, it would be acceptable).
On Halloween, changing things to look more spooky, maybe dressing up monsters into costumes (not something special, so it's more funny, and you can still recognise the original monster, for example bats with white cushion being ghosts).
There are many celebrations, like Valentines, Easter, Summer, so it might turn out to be pretty good.
How can this work? Well, it could be the game checking server date, or client date (so if you change your date to Christmas, you would get hats).