Ok i had the time to test the linux version of all the games.
My setup is Archlinux 64bit on AMD64 Athlon X2 + Geforce 8400GS
THE RESULTS:
Psychonauts: it crashes randomly on cutscenes, framerate drops in some areas
Amnesia: it works, merely playable on minimum resolution/quality

Limbo: WINE (wtf?) crashes instantly

Bastion: unacceptable framerate even on minimum resolution (MONO wtf?)

SwordAndSorcery: it works great, at least

Sidenote: THE LINUX INSTALLER FROM HELL
What's the point in packaging games in that GOD AWFUL nixstaller?
I have to:
-unpack an 1 GB archive file just to obtain the installer setup
-launch the setup that explodes gigabytes into my tmp folder, blowing it away
-the installer proceeds to copy from /tmp into my folder of choice.
I have to waste an amount of HD space that's 4/5 TIMES
the size of the original package, just to install the damn thing.

In my dreams, uncompressing a TAR.GZ should get me straight
into the game by entering the directory and launching the startup script.
Not a good overall experience for Linux users, isn't it?