While there is no single official release titled "Doom Collection 2015," several classic compilations were available around that time, such as the Doom Classic Complete bundle on Steam . These collections typically include the foundation of the franchise: , DOOM II , and Final DOOM . Official Purchase and Download
DOOM Full Collection : id Software, GT Interactive - Internet Archive
For a legitimate and safe experience on modern PCs, you should use official digital storefronts. These versions often come pre-configured with DOSBox for immediate playability.