Portal appears for me in Linux Games but doesn't seem like it correctly installs (doesn't seem like it installs anything). Error is missing executable (and I already tried removing the appcache folder).

Processor Information:
    Vendor:  AuthenticAMD
    Speed: 3000 Mhz
    4 logical processors
    4 physical processors
    HyperThreading:  Unsupported
    FCMOV:  Supported
    SSE2:  Supported
    SSE3:  Supported
    SSSE3:  Unsupported
    SSE4a:  Supported
    SSE41:  Unsupported
    SSE42:  Unsupported

Network Information:
    Network Speed:  

Operating System Version:
    Ubuntu 12.04.2 LTS (64 bit)
    Kernel Name:  Linux
    Kernel Version:  3.2.0-40-lowlatency
    X Server Vendor:  The X.Org Foundation
    X Server Release:  11103000
    X Window Manager:  Mutter
    Steam Runtime Version:  steam-runtime-release-i386_2013-04-16

Video Card:
    Driver:  ATI Technologies Inc. ATI Radeon HD 3800 Series

    Driver Version:  3.3.11672 Compatibility Profile Context
    Desktop Color Depth: 24 bits per pixel
    Monitor Refresh Rate: 59 Hz
    VendorID:  0x1002
    DeviceID:  0x9501
    Number of Monitors:  1
    Number of Logical Video Cards:  1
    Primary Display Resolution:  1440 x 900
    Desktop Resolution: 1440 x 900
    Primary Display Size: 16.06" x 10.04"  (18.94" diag)
                                            40.8cm x 25.5cm  (48.1cm diag)
    Primary VRAM Not Detected

Sound card:
    Audio device: Realtek ALC892

Memory:
    RAM:  3826 Mb

Miscellaneous:
    UI Language:  English
    LANG:  en_US.UTF-8
    Microphone:  Not set
    Total Hard Disk Space Available:  335067 Mb
    Largest Free Hard Disk Block:  21446 Mb

Installed software:

Recent Failure Reports: