Contra is a 1987 run and gun video game developed and published by Konami for arcades. A home version was released for the Nintendo Entertainment System in 1988, along with ports for various home computer formats, including the MSX2. (via Wikipedia)
The genre Contra helped define
Run-and-gun. relentless side-scrolling shooting, co-op play, and spread-shot power-ups.
The game mechanics of Contra
Scrolling MovementTraversalWorld scrolls in one or two axes as the player moves or time passes; player exists within an advancing boundary.
Boss EncounterCombatA single high-health enemy with unique scripted behavior and distinct phases serves as a gated progress challenge.
Contact DamageCombatTouching an enemy or environmental hazard deals damage to the player without any explicit attack trigger from either party.