This could easily be, the best Sci-fi game ever made. The races are uniquie (None of this, "Hey! If we take a human, make them pale as hell, and give them robes, we have an alien!" crap that a lot of sci-fi shows tend to do. No, the races are quirky, the game area is huge, and when you beat the game, you'll feel like you lost a friend.
Download the game here. You don't even need an emulator.
http://prdownloads.sourceforge.net/sc2/uqm-0.5.0-installer.exe?download
If you want some screenshots about some of the races:
That tough-looking dude is a Thraddash. They have ships that use afterburners to propel the ship at an ungodly speed. The trail of fire left by the afterburners can damage any ship that goes through them. In reality though, their ships suck. The blasters on them are weak, and the shields on them are weak as hell.
These guys are the Spathi. They're the coolest guys in the game. They're funny to talk to, and they are very submissive in the face of pain or death.Their ships are very useful too, if you know how to use them. They're cowardly though.
The Zoq-Foq-Pik. They're a cool race to talk to, and they can never shut the fuck up about their own sport (Can't remember the name of it at the moment.) They be an interesting race, but their ships suck. Hard.