Linux can't launch Portal 2

I can't launch Portal 2 through Steam. Terminal gives me this:
Game update: AppID 620 "Portal 2", ProcID 22984, IP 0.0.0.0:0
ERROR: ld.so: object '/home/zvon/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
/bin/sh: 1: /home/zvon/.local/share/Steam/steamapps/common/Portal 2/portal2.sh: Permission denied
Game removed: AppID 620 "Portal 2", ProcID 22984
Generating new string page texture 271: 48x256, total string texture memory is 950.27 KB
Installing breakpad exception handler for appid(steam)/version(1426284031)
Installing breakpad exception handler for appid(steam)/version(1426284031)
any ideas on how to solve this?

Can you post the output of ls -l please?

total 900
drwx------ 11 zvon zvon 4096 Mar 14 14:13 bin
-rw------- 1 zvon zvon 94 Apr 6 2013 installscript_osx.vdf
drwx------ 8 zvon zvon 4096 Mar 14 14:13 platform
drwx------ 15 zvon zvon 4096 Mar 14 14:13 portal2
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_czech
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_danish
drwx------ 8 zvon zvon 4096 Mar 14 14:13 portal2_dlc1
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_dlc1_french
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_dlc1_german
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_dlc1_russian
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_dlc1_spanish
drwx------ 11 zvon zvon 4096 Mar 14 14:13 portal2_dlc2
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_dutch
-rwxrwxr-x 1 zvon zvon 358912 Mar 14 14:25 portal2.exe
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_finnish
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_french
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_german
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_hungarian
-rwxrwxr-x 1 zvon zvon 304942 Mar 14 14:25 portal2.ico
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_italian
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_korean
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_koreana
-rw------- 1 zvon zvon 5217 Jul 11 2014 portal2_linux
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_norwegian
-rw------- 1 zvon zvon 13148 Apr 7 2013 portal2_osx
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_polish
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_portuguese
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_romanian
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_russian
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_schinese
-rw------- 1 zvon zvon 1194 Jul 11 2014 portal2.sh
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_spanish
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_swedish
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_tchinese
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_thai
drwx------ 2 zvon zvon 4096 Apr 6 2013 portal2_turkish
drwx------ 4 zvon zvon 4096 Mar 14 14:05 sdk_content
drwx------ 3 zvon zvon 4096 Nov 18 18:50 sdk_tools
drwx------ 3 zvon zvon 4096 Dec 28 10:05 Soundtrack
-rw------- 1 zvon zvon 5 Jan 21 17:04 steam_appid.txt
-rw------- 1 zvon zvon 77312 Apr 7 2013 thirdpartylegalnotices.doc
drwx------ 6 zvon zvon 4096 Mar 14 14:13 update

This line says that user zvon has read write access to the file portal2.sh
This line also says that file portal2.sh does not have permissions to execute as a program.
If you right click the file and go to properties then permissions and click on
'allow executing file as a program'
Then it should work

by contrast this line
-rwxrwxr-x 1 zvon zvon 304942 Mar 14 14:25 portal2.ico
says that an icon file or picture has permissions to execute as a program.

Did that and did the same thing for "portal2_linux" and it works now, thanks a lot! :)

You're very welcome.