Focus is a game by the great game designer Sid Sackson. Those little round things that look like Scrubbing Bubbles in the photo above are the pieces; you stack them, up to 5 high, and a stack moves exactly as far as it has pieces -- 3-piece stacks move 3 spaces, and so on. You can move partial stacks. The colour on top controls the stack. If a stack becomes higher than 5, you take pieces off the bottom; tokens of your colour become reinforcements to parachute in later, and other-coloured pieces become prisoners. The goal is to control every stack on the board.
Focus plays brilliantly. It won the German Spiele des Jahres (Game of the Year) award in 1981, and has been published in many editions since the 1960s. The image above is a three-player game from an early Seattle Cosmic game night (15 Apr 2000), using the 1982 Milton Bradley "Domination" edition.
The two-player game is best; it is an AbstractStrategyGame, and a two-player Focus set can be improvised from two Checkers sets, which we intend to do for GamesToTheRescue, the group's philanthropic work. If you want to do so yourself, the instructions can be found in Sid Sackson's book A Gamut of Games.