Rain World (312520)

System:
Steam System information report
Kernel: 4.14.67-1-lts x86_64
Desktop Env: i3 4.15
Distro: Antergos Linux (Arch Linux based)
Device: laptop System: CLEVO Mobo: P370EM
CPU: Quad core Intel Core i7-3740QM (-MT-MCP-) 3700 MHz
Graphics:
GPU: NVIDIA GK104M [GeForce GTX 670MX]
Display Server: X.Org 1.20.1 Resolution: 1920x1080 60.02hz
Nvidia driver version: 4.6.0 NVIDIA 396.54
OpenGL: renderer: GeForce GTX 670MX/PCIe/SSE2
Memory: 16 GB

Two issues:

1. The main character (slugcat) is yellow, instead of white. Posted on Steam community forum here. This is normal.

2. (Wired) Xbox 360 controller doesn't work, no input at all. Posted on Steam community forum here.

3. Arguments were needed to launch: PROTON_USE_WINED3D11=1 PROTON_LOG=1 PROTON_DUMP_DEBUG_COMMANDS=1 %command%

Without these arguments, the game fails to launch. Here is the Proton log when PROTON_USE_WINED3D11 is NOT being used (and doesn't launch).
Here is the log with PROTON_USE_WINED3D11=1 (which works).

No source file, test, or entry point is named. Start by checking whether the wired Xbox 360 controller still produces no input on the reported Linux setup, then review the linked Steam discussion for reproduction details. Done means controller input works reliably in Rain World without relying on undocumented workarounds.