Well, I see a lot of aiming with the movement keys. It reminds me of how trackball players play.
Isn't that pretty standard even at higher levels of play? Like in CS I think you're supposed to keep your mouse on the level of where you anticipate you opponent to be and get him in sight by using your movement keys. I think I saw a video on that once.
It is pretty standard for the scout, where your advantage is movement speed and being hard to hit.
Does something like Brothers still require a controller? That might not be compatible then?
There is no reason why it shouldn't work. All the 360 controls match up to the Steam Controller. You probably couldn't use the pad as a trackball or mouse though since the game hasn't allowed that anyway, so you'd be stuck emulating analogue movement