Warhammer 40K: Space Marine's Master Crafted Edition had a rough launch, especially on the #SteamDeck. However, a workaround is now in place to at least get it to work while the developers work on a permanent fix:

https://steamdeckhq.com/warhammer-40000-space-marine-master-crafted-edition-is-finally-bootable-on-the-steam-deck-with-beta-patch/?utm_source=dlvr.it&utm_medium=mastodon