I'm looking for a two-player board game I played 20-25 years ago (in the Netherlands). The board is upright, as if it's kind of a wall, and players are sitting on opposite sides of the wall, not seeing each other's boards. The objective is to get small 'coins' from the top of the board to the bottom; the first player to do so wins. One player has red coins, the other one yellow. There are (blue, IIRC) wheels of various sizes in the wall; players take turns rotating these wheels. The wheels have 3-5 small cavities, evenly spaced, to hold the coins. The coins stay in the wheel because the rest of the wall holds them there, except for a few tunnels where they can fall to the next wheel. I think you cannot see where the cavities at your opponent's side are, this is the hidden information which makes the game interesting. Whenever you rotate a wheel to improve your own position, you might accidentally help your opponent forward as well.
This is a rough sketch of how a part of the board looks like: