Hello @Rexpulli, I'm going to mark this as a compatibility report instead of a whitelist request because the missing intro videos should be evaluated and fixed if possible. Please add PROTON_LOG=1 %command% to the game's launch options and attach the generated $HOME/steam-$APPID.log to this issue report as a file. (Proton logs compress well if needed.)
I added the report.
I should also mention that with the Media Foundation fixes from Proton 7.0rc3-GE the videos play fine, however the game itself is unplayable:

It should look like this:

The videos play without issue on proton 8. I see that valve is providing transcodded videos for this title, however, there's a small issue that can be seen in the video below, the unreal engine part of the intro is corrupted
https://github.com/ValveSoftware/Proton/assets/70454800/48de6b44-b742-4f98-930f-d946db33c9fe
You can easily play the video as it's a raw file shipped with the game.
Turns out it's buggy.
failcraft ivyl Snake Pass % mpv SnakeSimulator/Content/Movies/UE4_LogoPC_1080.mp4
(+) Video --vid=1 (*) (mpeg4 30.005fps)
(+) Audio --aid=1 --alang=eng (*) (aac 2ch 48000Hz)
AO: [pulse] 48000Hz stereo 2ch float
VO: [gpu] 1920x1080 yuv420p
AV: 00:00:03 / 00:00:05 (62%) A-V: 0.000
[ffmpeg/video] mpeg4: ac-tex damaged at 61 1
[ffmpeg/video] mpeg4: Error at MB: 182
... many many more ...
Both gstreamer and ffmpeg try to render the broken blocks. Trying to play the video on Windows it just hitches there - probably waiting on the next keyframe instead of trying to render the frames.
So it was broken from the start. To my knowledge, that was the only issue the game had so it's probably safe to close this.
PROTON_LOG=1x1 2022-01
Whitelist Request
System Information
I confirm:
Playbutton in the Steam client is sufficient.Issues
steam-544330.log