At the start of the video was the PC Port and the flickering in the main menu could just be a video driver issue or something. The rest of these looks like it came from the HD Collection which is infamous for all it bugs and such. Look up the history of Silent Hill HD Collection on KZfaq and you'll find good videos on people running down points on what happened. The HD Collection also have new voices for the characters for Silent Hill 2 and 3 and only SH2 are you able to toggle back to the old voices. For SH3 in the HD Collection, you are stuck with the new voices sadly. But lastly some of the glitches are from the PC Port as well. Like the out of bounds glitch.