Try turning off the posteffect and possibly set the shader detail to low and see if it is playable. However, you may have to get a better video card as the intel cards are not supported.
Supported Video Cards
frodo Wrote:P4 dualcore 3GHz, 1 GB ram, intel i945 onboard video card.
Debian etch.
Other opengl apps working perfectly.
PenumbraDemo-Beta3 (the patch didn't make difference).
I had to remove all the libraries in libs/ except libCg.so and libCgGL.so in order to avoid the glib version problem. I tried also that 2 libs from the nvidia download with no difference.