LIMBO (48000)

This game has native port, but that one doesn't even let me start a new game (black screen, everything frozen, only main menu works, by pressing ESC). On Proton, everything works flawlessly, until the very end...

Compatibility Report

• Name of the game with compatibility issues: LIMBO
• Steam AppID of the game: 48000

System Information

• GPU: AMD Radeon RX 5600 XT
• Driver/LLVM version: Mesa 20.3.1 (LLVM 11.0.0)
• Kernel version: 5.8.0-33-generic
• Link to full system information report as Gist: Gist
• Proton version: 5.13-4 (also tried 4.2-9)

I confirm:

• that I haven't found an existing compatibility report for this game.
• that I have checked whether there are updates for my system available.

Proton log: https://gist.github.com/mascherone108/fae46b5059fd794e00dc24678fb1b43d

Symptoms

Character in the last part freezes upon entering a "cutscene", making it pretty much impossible to finish the game properly. I have recorded a video that shows it better (SPOILER ALERT): https://www.youtube.com/watch?v=cylmM0Yk2k0
Notice that when I press ESC repeatedly the cutscene seems to move one frame at a time.

Reproduction

Just play the game till the end.

Start with the linked Proton log and the compatibility report's reproduction details, then compare the end-game behavior with the recorded video. The issue is complete when LIMBO can reach and finish the final cutscene without freezing under the reported Proton versions and system conditions.