No Rest for the Wicked is an upcoming ARPG from the devs behind the Ori games. From what I understand, it focuses on a slower more methodical play style than other ARPGs like Diablo.
Moon Studios co-founder Gennadiy Korol said on Xwitter that we can expect around "30-40fps" on the Steam Deck, depending on the quality settings. There are some dips to "20-25fps" and some cinematics might make that number "dip more". But thanks to their "Game Simulation", the game runs at a locked 60fps, so "the game input for the precision combat remains super responsive!". Korol goes on to say that this info isn't "official-official" yet and that they'll continue to work on performance over time.
"Image quality, performance dips and memory will be further improved as we will be patching and improving the game in the future. I really love how this game feels with Deck's locked 40fps screen and our 60fps game simulation and responsive input. So hopefully we'll be able to get to that locked 40fps target sometime after launch."
Here's the game's steam page, it launches in early access roughly 2 hours after this post.
Edit: early impressions for the game are out, and performance is much worse than how it was portrayed. I would recommend waiting for further optimization and fixes before picking it up unless you play to play on a much beefier PC.