The Test

The Test is a screamer video uploaded by psychologist Richard Wiseman for his Quirkology channel on YouTube.

Video
There are two versions of this video - a public version, which does not include any screams, and an unlisted screamer version, which won't show up in regular searches and is only accessible through links. Both versions include a face with the that pops up with a same scream from The Maze near the end, though.

The viewer is supposed to imagine being trapped in a cell with a killer who forces them to play a game involving sixteen green or pink Post-it notes which are arranged in a 4x4 grid.

Viewers are now told to place their finger or cursor on any of the green notes, and then make four moves according to the following instructions: The narrator then starts taking the Post-it notes away, explaining that if the player landed on any of these squares, the killer would let them go free. Eventually, only the green square in row 3, column 3 remains. At this point, the narrator slowly pulls this note away as well, revealing two white tapes forming an 'x', and explains that if the player landed on this particular square, it would mean that their “time has come” About a second later, a Halloween mask of a wrinkled face pops up close to the screen, accompanied with the same scream from The Maze in the unlisted version.
 * 1) Move left or right to the nearest pink square.
 * 2) Move up or down to the nearest green square.
 * 3) Move diagonally to the nearest pink square.
 * 4) Move down or right to the nearest green square.

The game featured in the video is, of course, unwinnable. Any of the eight possible starting squares will lead to the same square in the end if the instructions are followed correctly.

Links
NOTE : The following video contains a screamer!
 * youtube.com/watch?v=sZQOEBhP9R8 • Unlisted screamer version.
 * youtube.com/watch?v=ikbEBp5BeCM • Public version without the scream.