@ Enno -- Older-generation Intel HD Graphics GPU doesn't appear to support the shader effects required by the game. This could be why there is no ambient light (except for the "glowing" ocean) in the game.
You can take a look at this \Bright Light_Data\output_log.txt file in the game folder, & see if contains any of the following lines:
- D3D shader create error for vertex shader
- D3D shader create error for pixel shader
- ERROR: Shader Shader is not supported on this GPU (none of subshaders/fallbacks are suitable)"
- WARNING: Shader Unsupported: 'Hidden/BilateralBlur' - Setting to default shader