Yes, it runs very well. The only problem is that the launcher can be a bit flakey but I suspect that’s not specific to the Deck.

GTA Chinatown Wars (PSP version) on my Steam Deck. I tried GTAV first and found it a bit lackluster (it’s very well made, but it didn’t really grab me), then thought I’d try Chinatown Wars instead and I’ve been surprised how much I’m enjoying it.