One... Two... Freddy's Coming For You...

[The Artist Formerly Known as Hawk]

I think the river of blood thing was a homage to some other horror movie. It probably only did that becuase by then the survivors were getting ready to blow the ship apart and it needed something to stop them before sending them back to hell and its human manifestation hadn't yet ressurrected or was busy fighting the other guy in the engine room. Seeing as it spent most of its time trying to take over his mind I can forgive the slow growth of its manifestations.

Besides, it's evil, it doesn't need to immeditately bring out the big guns, I'm sure it had more fun slowly toying with the crew and then killing off a few of them.

But yeah that engine room was all kinds of messed up. Though seeing as the whole ships architecture was designed around a cathedral style I'm not surprised.