Eight years ago, Treyarch added a different game mode to the new “World at War” game in the popular “Call of Duty” franchise. This fresh game mode was “Zombies” — a classic idea with an insane twist, and an eerie storyline to be followed, or better yet, discovered.

In order to reveal this story line, players would have to do certain tasks and gather specific objects around the map to unveil an Easter egg, which in video game terms is a special achievement award obtained by solving puzzles. The zombie’s Easter eggs would become some of the most satisfying achievements in all of video games.

“Call of Duty” players made the zombies game mode a huge success for the entirety of the “World at War” game, as well as three other games that had the zombies mode, all of which falling under the “Call of Duty Black Ops” series with the game mode ending in the latest “Call of Duty” game “Black Ops III.” Now the final map is out and players and storyline followers are looking back feeling mostly satisfied… for now.

When “World at War” came out in late 2008, the new zombies mode, first known as “Nazi Zombies,” was a surprise and immediate fun. The first map was “Nacht der Untoten” (Night of the Undead), a map of an airfield in the eastern pacific that originated from the campaign. This map featured nothing special but the Treyarch Zombies basics: wall-buy weapons, powerups, doors to open, a mystery weapon box, and the first wonder weapon known as the ray gun. “Verrückt,” a German asylum, was soon to follow.

In this map, “Perk-a-Colas” (perks) would be introduced. Perks allowed players to survive much longer and achieve much higher rounds by giving the player more health, increased stamina and many other enhancements. “Verrückt” was also the first map with a miniature Easter egg; however, it would only be discovered nearly two years after the maps release.

Then “Shi No Numa” (Swamp of Death) came out. “Shi No Numa” was the first map to introduce the main characters of the zombies storyline: Tank Dempsey, Nikolai Belinski, Takeo Masaki and Edward Richtofen. These characters would carry the players through the entirety of the zombies storyline, including the very first map that seemed to precede the characters themselves.

Finally, “Der Riese” (The Giant) came out as the last delayed content (DLC) map for “World at War.” This map was the first to feature “Pack-a-Punch,” a point costly machine that would upgrade the entirety of your weapon and the inclusion of a map based wonder weapon: the “Wunderwaffe DG-2.” “Der Riese” was the first official map that included an official Easter egg to kick off the story line.

All four of the World at War maps became major hits and instant classics. They would set the stage for the rest of the Zombies epic.

About two years after World at War was released, “Call of Duty Black Ops” was introduced to the gaming world. This would be Treyarch’s second ever game with the Zombies mode. With each map, new storyline pieces were placed and were out to be discovered by the many Zombies fans. New maps included parts for buildable machines that would help the player achieve the Easter egg and higher rounds. Many new perks were also introduced as well as updated weapons. Boss fights were introduced in a small scale for the first time too. “Black Ops” also ushered in the alternate zombies mode known as “Dead Ops Arcade,” which was simple arcade like mode where a player would control the character in third person and try to survive the undead in a new fashion.

Another long time period would pass by and finally “Black Ops 2” would come out. This would also be the third edition of Zombies. “Black Ops 2” offered little in storyline at the time of its peak; however, it would bring in the banking system and the first ever full-scale boss fight. The majority of the game was based with other characters who would assist the four main characters achieve their goal. However, in the last map of the game, “Origins,” the four main characters returned and gave the players a hint about the new storyline to be discovered when the next Zombies game was released which would be about two years later.

Finally, “Black Ops III” was debuted in late 2015. This game would feature the ending of the Zombies storyline. It would be the first game to give player challenges and “GobbleGums” (a small powerup that could give the player various new abilities ).

The DLCs were slow to come but never failed to be rich in content for the players. With each new map, the focus was to draw closer to the final fight with the creator of the evil: The Shadowman. Now, the final ever Zombies map, “Revelations,” has been released. The first Easter egg of the many promised has been found and has disappointed the large crowd of fans to Zombies. However many still search for clues that could lead to an alternate ending. An ending that would allow the game to truly be concluded and put to rest forever.

Yet Zombies will always be one of Treyarch’s biggest successes. Many players will most likely return to the game that created the some of the most challenging and satisfying experiences a videogame has ever delivered.