Hello!
I just install Amnesia in Steam on Debian Sid amd64. It seems your script "run_steam.sh" doesn't function correctly: a part of the script is commented, so the game will never be launched in 64 bits. I modified it like that:
#!/bin/bash
# Steam claims they are going to put us in the app directory.
if [ $(uname -m) == "x86_64" ]; then
./checklibs.sh libs64 Amnesia.bin64
./Launcher.bin64
else
./checklibs.sh libs Amnesia.bin
./Launcher.bin
fi
the command "uname -m" exists on all linux distributions (whereas "arch" is not), so it should work for all linux distributions
I also had to move the .so files from libs64/all/ in libs64/
Otherwise, I'm impressed to see how well the game runs on Linux! It seems to be as good as on windows.