It's so fun, with gore, japanese characters, mecchas, BIG GUNS, and awesome single player levels!
In my opinion the Lithtech engine has done its time... There are several bugs very annoying on the newer PC like the foes with extreme low reaction time (more like wallhack, heh). This drawback is also to be mentioned on Shogo's brother, Blood 2, sadly.
Few missions will stay in my mind, like fetching a cat to open some gates and solving little puzzles to break the gore (yes, the game is very gorish).
So put apart the Lithtech engine, it's a very good game with a lot of action and very cool stuff (pictures, easter eggs...) Definitely worth it. Oh, did I mention it contained two different endings? Well in one you get a big BIG gun...