I'm sure our group isn't the only one to try this, but has anyone else out there tried playing a campaign using only an alien race for characters. Our group used the rules for Ork characters to play an Ork freebooter campaign as a change of pace. It was a lot of nihilistic fun as the group travelled around the expanse looking for fights and looting opportunities. Most characters got to about 5th or 6th level before everyone died in an epic fight aboard an Imperial cruiser that the group rammed with their own ship. As I said, it was more of a fun, light-hearted game played for a change of pace.
Now that the rules for Dark Eldar characters are out, our group is pretty keen to have a go at playing a pillaging group of these aliens. It might turn out a bit darker than playing Orks though (pun intended).
I'd be interested to hear if other groups have done anything similar and how it turned out. Any suggestions for making a better game are more than welcome.
Cheers,
LT