Lemmings

Lemmings is an arcade game where your goal is to rescue lemmings that have escaped into the city from the sewers beneath. You play as an SPCA worker who must usher the aforementioned animals to safety within the buildings of the city. Complicating this is a delivery truck that will intermittently squash the lemmings they encounter.

Each building has 4 doors, and a door is closed when a player exits from that direction. Lemmings come in male and female variants, and the player must place 2 same-gendered animals in a building and shut all 4 doors to rescue them. If opposite genders are placed in a building, they will immediately escape after spawning a third animal. Lemmings will escape from a building if not placed with a friend and all 4 doors closed in a short period of time. Infected green lemmings are regularly spawned, and if the player encounters these, they lose a life. These animals have a limited life expectancy before expiring.

The player receives 6 points for every lemming they usher into a building, but will lose them again if they escape. They receive 50 bonus points for every animal duo safely rescued. When all buildings have been filled, the player advances to a more difficult stage. You have a total of 3 lives, if all are lost it's game over.