For me, at first, the dogs were terrifying. Early on, I looked for every way I could just to get AROUND their patrol rather than having to sneak through it. I did not kill my first dog until I found the biologist's lab. For some reason, I was under the assumption that the door to Shaft 12 was locked, so I found myself running in circles for quite some time. And since every time I needed to get to a major room I needed to pass a dog.. I got a little sick of it. Finally, I just started systematically killing them all. Now not only did I realize that they weren't all that scary, but there was NOTHING left to give me pause. A welcome relief considering I had to make about three or four more trips through that area. My first encounter with the Rock Worm was more comical than terrifying, as I tried to hide in the shadow near the door. I only had a brief second to be startled as the creature ate me before laughing at how foolish my plan had been with a "Well, that was dumb. Plan B". The second encounter however WAS scary- running for my life with the worm nipping at my heels. At the ending of Overture, I saw the silhouette in the distance, and slowly walked towards it. As the lights went out, I gathered my courage, drew my pick-axe, and ran at it in a blind and brave battle charge. We all know how THAT turned out.
A day or two passed before my adventure continued- I got Overture through the humble indie bundle, and did not yet have Black Plague. Overture took me by such surprise I could not help but buy the rest of the series. What I had expected to be a dumb twenty minute distraction had kept me on the edge of my seat for an entire night, and kept me adventuring even the next day.
Then I saw my first Tuurngait. When I heard it coming I shrugged, ducking into the nearest dark corner. Then it opened the door and walked in. My heart stopped.
As the game continued, I found that the way in which enemies were handled had vastly changed. No longer was there an enemy waiting around every other corner. No longer was an enemy as simple to deal with as sneaking behind it and bludgeoning it to death. Running and hiding were now my only viable options. These enemies were almost perfect, except for one small issue- There should be a feeling of terror when cornered, and almost a certainty of death. Instead, all one had to do was wait until the Tuurngait got close and then bolt past them- the chase was now on once more, and the chances of running into another dead end became near zero. Often times the Tuurngait would not even manage to strike you as you zipped past it. Even still, I much prefer Black Plague's handling- They're far and few between, keeping them from being an utter nuisance while getting from point A to point B. However at the same time, they're considerably more dangerous, and a persistent threat that you can't kill and be done with.
It should be noted that I was basically always on the edge of my seat, spending most of my time sneaking without my flashlight or glow stick ever active. The only time I was ever satisfied that there was no enemy around the corner was the instance in which I knew there HAD been and I'd already killed it.