I used to play a pc game years ago, but can't remember the name of it. More info below...?

I thought it was called something like Space Marines, or Battle Marines or something. You commanded a squad of about 5 or 6 guys and the levels resembled a giant spaceship, or base on an alien world or something. I know it's not much to go on, but I've been looking for this game on & off for the last 7-8 years, so any info would be greatly appreciated!!!