Unlike the modern Steam version, which has its own launcher, version 1.55 is launched differently.

So, what does the "full 155 install" actually give you? When you install this version, you are getting the complete Cry of Fear experience as it existed in its mod form. This includes:

Cry of Fear v1.55 requires OpenGL rendering. If your modern graphics card (NVIDIA RTX or AMD Radeon RX series) rejects the legacy driver request: Open your GPU control panel.