I currently own (to my dismay) this game on Steam. Now I haven't had any performance issue but, you know, all the rest is there. No story. No Multiplayer. Tedious and repetitive gameplay. Barely any space combat, and what is there is mediocre at best. Near-infinite universe that is hollow inside. No base building. No customization. and the list goes on The game is overpriced even at 40% off. DO NOT BUY. You will regret it.
I currently own this game on Steam and...on CD-ROM! I own this copy since I was 6-8 years old, and man does it still hold up today. You play as 1 of 3 (1 unlockable) character that must go through a giant citadel in order to destroy the last boss and prevent a cataclysmic event. Nothing too innovative here in term of story. Where it shines the most is the creepy atmosphere, the ton of guns with special functions and the enemies that can pose a threat to you, not to mention the level design. It's quite long too.