Plants vs. Zombies' multitasking between lanes was influenced by the arcade game Tapper.
Tapper, released by Bally Midway in 1983, puts the player behind a bar serving drinks to customers arriving along several parallel lanes. The central challenge is not merely reacting quickly; it is dividing attention across lanes, sending service at the right time, and preventing one queue from reaching the player. That structure helped inspire the way Plants vs. Zombies asks players to monitor simultaneous threats across a lawn.
In Plants vs. Zombies, each row behaves like a lane. Zombies advance from the right, and plants generally attack along their own horizontal row, so a player must watch several fronts at once. A crisis in one lane can demand immediate action even while another lane needs sun collection, planting, or protection. This creates the game's characteristic multitasking pressure.
Tapper did not provide the tower-defense system itself. Plants vs. Zombies also draws on strategy games, gardening themes, and PopCap's earlier casual-design experience. The arcade influence is more specific: it helped shape the spatial idea of multiple lanes carrying threats toward a defended position. Q*bert, Dig Dug, and Centipede are plausible arcade guesses, but Tapper is the documented inspiration for this lane-management aspect.