RPCS3 now automatically adds PS3 games to your Steam library, removing manual setup and streamlining the emulation experience ...

RPCS3 has introduced a new user interface workflow that allows players to add emulated PlayStation 3 games directly to their ...

The Xbox app on PC now lets you manually add any game or app to your library. Learn how this new feature works and why it is ...

You can now add third-party games to the Xbox app on PC, a feature that feels tailor made for Microsoft's Project Helix ...

TL;DR: Microsoft's new Xbox PC app update introduces an aggregated gaming library, allowing users to launch and manage PC games from multiple storefronts like Steam and Battle.net in one place.

While you must be eager to play Marathon Server Slam, the current scenario is restricting the majority of the players from doing that, resulting in a "failed to launch on Steam" error.