Haven't tried penumbra yet, but I certainly will!
Got Osmos packaged up and installed easily enough:
src2pkg -N Osmos_1.6.0.i386.rpm
src2pkg -VV -C -W -X Osmos_1.6.0.i386.rpm
Again, the proprietary nvidia driver seemed to be needed for it to work properly on my hardware. I previously installed openAL from slackbuilds.org which is needed for the sound.