Complete the Collection
The urge to collect all the items, achievements or secrets in a game.
The desire to collect things is a strong urge that game developers often exploit to get you to keep playing a game with the hope that one day you'll find all the rare items and have a complete set.
For people who collect things, the collection can have significant emotional value. It may connect them to something that they enjoy or feel strongly about. Some people collect for the thrill of the hunt, others may collect because it gives them a sense of security or control. Others may derive great satisfaction from having a complete set and feel anxious when they are missing a piece of a set.
All of these psychological effects contribute to making you keep playing the game, even if the "playing" of the game is not enjoyable anymore. If game developers are constantly releasing new content, then the players are always needing to "catch up" and may feel like they need to spend money to do so.
Sometimes reaching the 100% completion rating in a game can take hundreds of hours of additional tedious work beyond the normal scope of the game. Sometimes, some of the collectable items are only available via special events, and because players may have a fear of missing out on those items, they will continue playing and paying, even if the game is no longer fun.
For people who collect things, the collection can have significant emotional value. It may connect them to something that they enjoy or feel strongly about. Some people collect for the thrill of the hunt, others may collect because it gives them a sense of security or control. Others may derive great satisfaction from having a complete set and feel anxious when they are missing a piece of a set.
All of these psychological effects contribute to making you keep playing the game, even if the "playing" of the game is not enjoyable anymore. If game developers are constantly releasing new content, then the players are always needing to "catch up" and may feel like they need to spend money to do so.
Sometimes reaching the 100% completion rating in a game can take hundreds of hours of additional tedious work beyond the normal scope of the game. Sometimes, some of the collectable items are only available via special events, and because players may have a fear of missing out on those items, they will continue playing and paying, even if the game is no longer fun.
Examples
Township"a Museum building offers premium currency for gathering rare artifacts"
Monster Legends"There's a library in game that grants rewards for completing collections of monsters. Each monster is categorized into a "book" of up to eight monsters, and collecting all monsters in the book grants a reward. This is in addition to a global monster collection counter that appears when at your base."
Asphalt 8: Airborne"Used to have a collection system which rewards you for owning a certain amount of cars from a particular collection."
Dead by Daylight Mobile"The game has a page where all cosmetics are displayed for each character, showing blank spaces and a counter of missing parts of the "complete collection"."
Single City: Life Metaverse"avatars, roomies(characters), limited furniture"
The Walking Dead: Survivors"Collect and build to earn achievement and reward"
Temple Run"There are collectible characters"
Solitaire Cash - Real Money"Seasons of card collections, large reward if you get all of them- but you get more and better cards by gambling more money."
Polysphere"Some of the puzzles are paywalled, so even if you want them all you can’t without money"
Life Makeover"This is a clothes collection game"