Downfall Ad (1999 UK)

About Downspin, from BoardGameGeek:

A head-to-head strategy game of cause-and-effect with a twist-literally. Players face off across a shared vertical screen rigged with five interconnected knobs. Behind this screen, each player loads their colored discs (numbered 1 through 5) into chutes at the top. On your turn, you twist a knob to move your own disc downward-but the catch is that the knobs operate differently on each side of the screen. What moves your disc forward might inadvertently help-or sabotage-your opponent! To win, be the first to get your discs to the bottom in perfect order... or cunningly force your rival's discs out of sequence. Quick thinking and risk-taking make this contraption game a puzzle, a race, and a psychological standoff in one. Several variants are offered in the rules. 1994 Mensa Select