the game launches Valve logo is showing and a glimpse of the title too then it just crashes.
The OS is an ubuntu derivative (elementary OS) 64bit.
Nvidia proprietary drivers are properly installed.
Running wine-1.5.9 Steam.exe steam://rungameid/620 (Working directory : /home/pier/.PlayOnLinux/wineprefix/portal2/drive_c/Program Files/Steam)
[0324/050933:ERROR:network_change_notifier_win.cc(111)] WSALookupServiceBegin failed with: 8
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
wine: Call from 0x7bc4c100 to unimplemented function ADVAPI32.dll.StopTraceA, aborting
[0324/051018:ERROR:network_change_notifier_win.cc(111)] WSALookupServiceBegin failed with: 8
Assert( Assertion Failed: (::DeleteObject( hOldBitmap )) ):surface_gdiwin32.cpp:1839
Shutting down. . .
[2013-03-24 05:09:31] Startup
[2013-03-24 05:09:31] Verifica dell'installazione in corso...
[2013-03-24 05:09:32] Verification complete
[2013-03-24 05:11:01] Shutdown