Elden Ring Nightreign Steam Deck Impressions – Recommended Settings | RPG Site

Check the article for more details, but here's the key part:

Whenever a game has some form of anti-cheat included or is online-focused, I worry whether it will run on Steam Deck or fully support the online modes. Not only does Elden Ring Nightreign boot up fine, but it also plays well even in multiplayer sessions. Before getting to recommended settings, I set the game to the low preset to see how much performance I could get out of it at 720p. In the four hours I've spent on Steam Deck with it in multiplayer and a bit more playing solo, the former is definitely more demanding. I had a few instances where it dropped to the mid 20s in very particle-heavy moments, but it otherwise held a frame rate of above 30fps very well.

The author also mentions setting everything as low as it could go, but that they were unable to hit 60fps.