Third party launcher requirement is documented in the store page.

Early Access titles whose last update was more than 2 years ago have a special note about it in the blue box.

The playability of low-population multiplayer games is the developer's and/or publisher's responsibility, not Valve's.

Valve will not force developers/publishers to forego DRM, including DRM that requires an internet connection for authentication.

There is a warning for 3rd party launchers already.

The rest is subjective or one can check the game's stats for player base, though not all multiplayer games are on Steam exclusively so it may not be accurate.

A little self research goes a long ways too.

SP games are dependent on the developer and not Valve's decision. A live service game could still be single player or require servers for aspects of the game (Diablo 4, for example).

Thank you for that. I’m new to Steamdeck (clearly. lol).

Valve's policies cover content on Steam
(no hate speech, illegal content, real person nudity), user conduct (no cheating, harassment), IP usage (generally allows free mods, commercial use rare), and specific rules for video creators (non-commercial use of assets,
YouTube monetization okay), plus refunds and data privacy, all governed by the Steam Subscriber Agreement and Steamworks guidelines.
Key areas include 'content guidelines', online conduct, refund rules, and IP/asset usage, with a focus on maintaining a safe, legal, and functional platform.

引用自 Jaunitta 🌸：

Valve's policies cover content on Steam
(no hate speech, illegal content, real person nudity), user conduct (no cheating, harassment), IP usage (generally allows free mods, commercial use rare), and specific rules for video creators (non-commercial use of assets,
YouTube monetization okay), plus refunds and data privacy, all governed by the Steam Subscriber Agreement and Steamworks guidelines.
Key areas include 'content guidelines', online conduct, refund rules, and IP/asset usage, with a focus on maintaining a safe, legal, and functional platform.

What does this have to do with the thread?

引用自 Jaunitta 🌸：

Valve's policies cover content on Steam
(no hate speech, illegal content, real person nudity), user conduct (no cheating, harassment), IP usage (generally allows free mods, commercial use rare), and specific rules for video creators (non-commercial use of assets,
YouTube monetization okay), plus refunds and data privacy, all governed by the Steam Subscriber Agreement and Steamworks guidelines.
Key areas include 'content guidelines', online conduct, refund rules, and IP/asset usage, with a focus on maintaining a safe, legal, and functional platform.

And yet the hate speech part isn't even enforced, instead anyone calling it out tends to get censored.

As for the launcher requirements, the launcher should be bundled with the game when downloaded.

The warning appears in cases where an additional account is required to play, or if any DRM restrictions beyond standard Steam DRM are present (online activation requirement, activation limits, etc.).