collectathon 

It refers to the genre of video game in which players find themselves compelled to search for tons of collectable items

Many games produced by Ubisoft , such as Far Cry and Assassin Creed, are collectathons

collectathon by XiongYonghang May 10, 2017

Collectathlon

A minigame wich can be played both in real life and in videogames such as Minecraft were the main goal is to collect as many hiddens items as possible, usually with a timer

'Welcome everybody to the Ba Sing Se anual Collectathlon!

Collectathlon by NotBananaSlayer January 4, 2022

Collectaholic 

A person who collects a f*ck ton of something (Ex: Books, Pencils, Artwork)

Eric: "Why the f*ck do you have so many books?!"
You: "Because, I'm a Collectaholic!"

Collectaholic by ItzQuk March 27, 2019