United Federation?

[rudeboy]

Has anyone been able to get this achievement? I have played through 4 times now (3 times killed by the flag ship but managed to get it the fourth) and only ever seen 5 races:

Human
Rockman
Mantis
Zoltan
Engi

What is the mysterious sixth race and where can you find them?

[curithwin]

That is the hidden race you need to open up the last vessel. I don't want to spoil it for you, but check cryo pods...

[Postal]

curithwin, the "secret race" isn't needed for the achievement he's talking about.
OP, you're missing Slugs on your normal list.

You should have:
Human
Rockman
Mantis
Zoltan
Engi
Slug

[rudeboy]

Weird, I've played through a bunch of times now and never seen slugs for sale or picked one up from a random event. Now that you mention it, I remember seeing them board my ship, but never gotten one in my crew...

[Sick Boy]

i see them less than others, but they're findable.

[fall_ark]

Weird, I've played through a bunch of times now and never seen slugs for sale or picked one up from a random event. Now that you mention it, I remember seeing them board my ship, but never gotten one in my crew...

They only spawn in Nebula sectors (Uncharted nebula, Zoltan Controlled, Zoltan Home, Slug Controlled, Slug Home). Slug sectors also have certain events to give you slug crew.

[HumbleSloth]

It took me about 30 runs to complete it. It is hard, the slugs seem pretty rare. I had a lot of runs where I got to 5 and couldn't find a slug to round things out.