[Psitticine]

I disagree as well. One of things that makes any monster really frightening, or at least particularly interesting and memorable, is the environment in which it dwells. Sometimes, it's the fact a monster has entered the realm of the everyday that makes it especially disturbing, but, in gaming, it is usually the fact the adventurers have ventured into the weird world of the dungeon.

In a sci-fi game, that environment can be just about anything. The adventurer can be far more the alien, forced to carry environmental gear and/or remain inside his ship, that little bit of "home" he's brought with him.

Venturing out to confront a sci-fi monster in its own alien world can be just as frightening, if not more so, than battling something in the claustrophobic depths of a dungeon. It also gives you the opportunity, albeit now a rather cliched one, to reverse the situation when the alien comes onboard the ship for the final battle.