I suggest everyone read "Best Practices for Cataloging Video Games, Using RDA and MARC21, Version 1.1, April 2018" found at
https://www.olacinc.org/sites/default/files/Video%20Game%20Best%20Practices-April-2018%20Revision-a.pdfEspecially the following sections:
II. General Characteristics of Video Games
Platforms and Formats .......
Editions and Expansions ......
Locating Credits and Title Information ......
IV. Describing the Resource
A. Attributes of Manifestation and Item (RDA Section 1)
1. Mode of Issuance
2. Comprehensive, Analytical, Hierarchical Description
3. Guidelines on Transcription
4. Title (RDA 2.3)
5. Statement of Responsibility (RDA 2.4)
6. Edition Statements (RDA 2.5)
VI. Resources
Online (Section), that lists:
Gamer Group
http://gamer.ischool.uw.edu/.
Good Old Games
http://www.gog.com/Moby Games
http://www.mobygames.com/ Play Asia
http://www.play-asia.com/Steam
http://store.steampowered.com/