Ragmand: I know this topic is 4 years old, but there's a similar problem now. I had this experience with libfmodex64.so.
libGLEW.so is included with the game, as is libfmodex64.so, the problem is that the startup script is badly written. In ~/GOG\ Games/Mount\ Blade\ Warband (or wherever you installed the game), you have to add the line
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:"`pwd`/game" between the
#Action and
run_game() { in start.sh.
$LD_LIBRARY_PATH is consulted at runtime by ld, the dynamic linker (finds all of your shared libraries (Linux equivalent to Windows' DLLs)). The game includes all of the necessary dynamic libraries, which is the good and correct thing to do, but the script left out this crucial step. I wouldn't expect a new Linux user, or even a semi-experienced one without programming experience, to know this or figure it out.
Hey! Thanks a lot for that. I want to add one more thing. Even after doing that, the game didn't work. So I ran it inside the terminal and noticed the error
Running Mount & Blade: Warband
Error: Unable to find module info file
So I ran the
mbw_config_linux file and just saved&quit. This probably created that needed file and I was able to run the game now.