I’m not sure what compelled Konami to make this announcement; other than maybe other developers prepping their games to be Steam Deck friendly… But they released an announcement the other day about the Castlevania Advance Collection stating the following:
Before purchasing this software, please be advised that it cannot be played on Steam Deck as it does not support SteamOS.
For the record, it does run under Linux/SteamOS just fine with Proton. It’s quite evident that Konami has no idea how Proton works under SteamOS/Linux. Hell, they didn’t even bother to try testing it themselves with a Linux distro, or ask a third party to verify that it works. Also, out of all of the games they’ve released on Steam, why did Konami choose the Castlevania Advance Collection? Quite a few of their other games have been verified to run on the Steam Deck (the Metal Gear games being among them) and they just randomly choose to post an announcement about a game that doesn’t work on Steam Deck… even though it does?
I haven’t played much of it myself, but I can verify that it runs under Manjaro on my Linux powered Surface Pro, which is very similar to current SteamOS. It would have almost made sense if they posted an announcement about a more resource demanding game not working on SteamOS. It would still have been wrong, but at least Konami would have been aiming a little higher, a little more graphically demanding.
Sometimes if you don’t know about how something works, it’s best not to say anything at all.