Tapper Commodore 64

Belly-busting Soda fountain fun, including: Mad-Cat, soda-starved,  clambering Cowboys, sports fans, punks, and space creatures. Plus a  head-spinning Soda Bandit Bonus Round Awesome colour-packed action  graphics. Just try to keep your cool as hot headed, crazy customers  blitz your bar for another cold one. — Cassette cover

Tapper, also known as Root Beer Tapper, is a 1983 arcade game  released by Bally Midway. The goal of the game is to serve beer  (or root beer) and collect empty mugs and tips.

Gameplay

The Tapper game screen features four bars. Patrons arrive periodically  at the end of the bar opposite the player and demand drinks. The player  must draw and serve drinks to the patrons as they slowly advance towards  the player. If any customers reach the player's end of the bar, they  grab the player-as-bartender and toss him out the far end of the bar,  costing the player a life.

The player serves customers by filling a mug at one of the four taps.  Once the mug is full, the player releases the tap which automatically  slides the mug towards the advancing customer. Customers catch mugs  that are slid towards them, as long as they are not already drinking  a beer, or otherwise distracted. If a mug is not caught by a customer  (whether the customer is already drinking or distracted, or if there  is no customer), then it falls off the bar on the other end, resulting  in a loss of a life for the player. If a customer does catch the mug,  though, then he or she is pushed back some amount towards the opposite  end of the screen. The goal is to push the customer completely off the  screen, but if they are not then they will stay and consume their  drink in place. When a customer finishes his drink, he slides the  empty mug back towards the player, after which the customer resumes  his advance on the player. The player must collect the empty mugs  before they reach the end of the bar and fall to the ground, as a  mug falling to the ground costs a life.

Source:Wikipedia