"- pshhhspp - this is the S.S. Ayedeekay -- sshpss -- we're being attacked -- ssshp -- some sort of green blob --- ssshhhsshshshsshshshsssss "

It was supposed to be a normal supply run to the outer colonies.  Out of nowhere a fast moving green slime overtook your vessel, surrounded it, and killed all of the crew.  You barely made it out into a nimble escape pod, and now must escape the slimes.