Avalanche (marble game)

Avalanche (also sold as "Lawine" in the Netherlands, and "Skill" and "Astroslide" in Germany) is an abstract, mechanical strategy game featuring colored marbles and plastic 'gates'. It was designed by Frank W. Sinden and published by Parker Brothers in 1965.
Gameplay.
The marbles are inserted at the top of the board, where they roll down until they hit a gate. If they hit the top of a gate they get stuck, if they hit the bottom 'feet' of the gate it is rotated and the marble that may be stuck on the gate will be released, potentially triggering a chain reaction. The players try to release as many marbles as possible during their move.
It was recommended for 2–6 players.