Editions are special versions of the Chicken Invaders episodes that are based around certain holidays. They come with the original version if you buy one on InterAction studios website, or as DLC on Steam. The only game that doesn't have any edition made for it is Chicken Invaders, and it's unlikely that Universe will receive them as well, due to how it's supposed to work.
Editions usually replace graphics, sounds and music of the game with stuff related to the things they cover.
So far, there have been four different editions.
These editions usually have the most effort going into them, with most of the graphics, sound and music being replaced. For example, only the Henterprise theme remained intact in Cluck of the Dark Side's Christmas edition.
Most InterAction studios games, including Piggly, Island Wars 2 and Loco also receive those editions.
These editions usually have the least effort put into them compared to other editions. Only the graphics and sounds get replaced.
Easter editions are being made since Revenge of the Yolk, however Cluck of the Dark Side hasn't received an Easter edition yet, and it's unknown if it ever will. Revenge of the Yolk and Ultimate Omelette are the only InterAction studios games to have an Easter edition.
In these editions, the graphics and the main theme music is replaced. They are unique from other ones in that the cutscene and in-game text is changed appropriately, since Chickens get replaced with turkeys. It was also why this edition started out with English being the only language available.
Thanksgiving editions are being made since Ultimate Omelette, and so far it's the only game that has a Thanksgiving edition.
Those only have the graphics, sounds and the main theme replaced.
Ion Blaster Gift • Neutron Gun Gift • Laser Cannon Gift • Vulcan Chaingun Gift • Lightning Fryer Gift • Plasma Rifle Gift • Utensil Poker Gift • Boron Railgun Gift • Photon Swarm Gift • Positron Stream Gift • Atomic Powerup
Ion Blaster Gift • Neutron Gun Gift • Laser Cannon Gift • Vulcan Chaingun Gift • Lightning Fryer Gift • Plasma Rifle Gift • Utensil Poker Gift • Boron Railgun Gift • Photon Swarm Gift • Positron Stream Gift • Hypergun Gift • Riddler Gift • Corn Shotgun Gift • Atomic Powerup