So this is not a very good game. Think of the cheapest, cheesiest horror movie you've ever seen, and then turn it into a game and you've got Blue Stinger. Terrible voice-acting. Cheesy "monsters". The story is some thing about dinosaur DNA returning and mutating creatures. The graphics look more akin to PS1 than what you'd expect from Dreamcast. And the gameplay just feels a little off. The way you're characters walk just feels awkward.
So it's not really any one terrible thing about this game. It's more a bunch of little things that just add up to a bad whole.
Unless you're big Dreamcast collector, I'd stay away from this one. If you want good survival-horror just get the Resident Evil games on Dreamcast. And Carrier is a good alternative on Dreamcast if you've played through all the REs already.