Controller

[DeerClipse]

Doesn't register my controller at all. Anyone else?

[🦊Λℚ𝓤ΛƑΛᗯҜᔕ🦊]

The steam store page does say "Partial Controller Support". Which usually means that not all controllers are guaranteed to work with this game. It seems that unfortunately you may have found one where it's not supported. :(

Fortunately this is a PC game though. You can still play it with a mouse and keyboard.

[Calmly Frenetic]

Depending on the type of controller, support should be available either in-game or through Steam Input. But in each case you will need to disable a Steam feature for it to work:
https://steamcommunity.com/app/2012840/discussions/0/3723944912968907788/

Regarding "controller support" for games on Steam, see here:
https://help.steampowered.com/en/faqs/view/3725-76D3-3F31-FB63#controller

[RealKarl]

Controller partially works if you disable Steam Input on the game's property page, but it's so buggy it's hardly worth it. You can't adjust any of the controller settings, and it's super sensitive. I have to invert right stick up down using Xbox Accessories. If I accidentally click the left stick, it brings up the controller keyboard and settings take effect, which won't go away unless I exit the game. I'll try to complete the game though, it does look pretty amazing.

EDIT: If I disable Xbox controller completely in steam settings, it works better. No keyboard shows up, and the Portal gamepad settings actually works. It was probably Steam desktop controller support that accidentally messes up Portal's use of gamepad.