Haha. Wikipedia spoilt it already:
"The ending of the game is somewhat questioned on whether or not the protagonist, Rush Sykes, survived at the end of the game, but after the game's credits Rush is heard talking to someone (most likely The Conqueror); the dialog says: "What will you do now?" Rush answers with "What do you think, I'm going back, they're waiting for me," somewhat revealing that Rush survived at the end of the game, although the current location of Rush and The Conqueror is unknown (possibly due to the screen being pitch black). It has been speculated that this may be a setup for a sequel."
Keep your mouth shut too