Your title says Seasonal times , but your poll only gives the option if Yes for a Halloween (that is not a Season) Winter is a Season , and plenty of other games have Winter Festivals that do not favor any one religion and make up their own Fictional holidays in the game Destiny could have a Winter Feast-Ival . they could put a quest line in-game for all players to find the pieces of the first guardians ship, Turn in the pieces to certain NPC's to get seasonal rewards like outfits or hats or sparklers, fireworks ,etc and the ship would slowly get assembled over the course of a couple weeks, up near where the Iron Banner is ( it's a big large empty space up there. Once the ship is fully assembled they could shine spot lights with faction emblems onto the ship , and have it snow. There are many ways they can add in many seasonal and other events through the year, they just need to be creative with them and the fun rewards that come with the events