Yup I have completed the first game (Criminal Origins).
It was scary at times and melee combat adds to the scare factor. Some psychological effects were too haunting.
The shool level was the scariest one, i still get creeps imagining the teacher who was locked into a locker with one arm amputated.
Ending was a bit shocking, how come he too was among them, may be he just lost his sanity at the very end and became a part of the cult.