Hi,
the game simply crashes when DISPLAY is unset (or any other initialization error occurs).
Maybe you could add an error message of what went wrong?
philipp@hiroshima ~/PenumbraEp1Demo $ echo $DISPLAY
:0.0
philipp@hiroshima ~/PenumbraEp1Demo $ unset DISPLAY
philipp@hiroshima ~/PenumbraEp1Demo $ ./penumbrademo
./penumbrademo: line 2:  6880 Segmentation fault      LD_LIBRARY_PATH=./lib ./penumbrademo.bin
philipp@hiroshima ~/PenumbraEp1Demo $ LD_LIBRARY_PATH=./lib gdb ./penumbrademo.bin
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This GDB was configured as "i686-pc-linux-gnu"...
(no debugging symbols found)
Using host libthread_db library "/lib/libthread_db.so.1".
(gdb) run
Starting program: /home/philipp/PenumbraEp1Demo/penumbrademo.bin
(no debugging symbols found)
(no debugging symbols found)
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[Thread debugging using libthread_db enabled]
[New Thread -1228306736 (LWP 6893)]
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1228306736 (LWP 6893)]
---Type <return> to continue, or q <return> to quit---
0xb7809f37 in SDL_GL_SetAttribute () from ./lib/libSDL-1.2.so.0
(gdb) bt
#0Â Â 0xb7809f37 in SDL_GL_SetAttribute () from ./lib/libSDL-1.2.so.0
#1Â Â 0x0837c152 in ?? ()
#2Â Â 0x082ccdd9 in ?? ()
#3Â Â 0x0831ea90 in ?? ()
#4Â Â 0x0831f537 in ?? ()
#5Â Â 0x08116a74 in ?? ()
#6Â Â 0x0813bd5d in ?? ()
#7Â Â 0xb7873838 in __libc_start_main () from /lib/libc.so.6
#8Â Â 0x0804d711 in ?? ()
(gdb)