devtrackers.gg
A German game-news-site wrote yesterday that factorio is indeed NOT RUNNING on the steam deck. At least as of now.
German sauce: Https://www.pcgameshardware.de/Steam-Deck-Hardware-277668/News/Nicht-kompatibel-mit-allen-Spielen-1387674/
It does run on the SteamDeck, we've had our hands on a unit for a while.
The only problem is the control scheme, naturally controller isn't best for a game built around Keyboard and Mouse, but we have some plans to try and get it working better.
EDIT: Here is a picture I took of it running our ~200spm 1.1 playtest, and its gets just under 60ups: https://i.imgur.com/SuuGJ88.jpeg
