Wolfenstein
The "Wolfenstein" series of video games started with the 1981 stealth-adventure video game "Castle Wolfenstein". It was developed by American programmer Silas Warner, a pioneer in the early eras of video gaming, especially the stealth genre. It was published by his (then) company M.U.S.E. Inc. (Muse Software). The player controls an unnamed American prisoner of war as he steals war files containing information about secret German war plans while avoiding or sometimes killing guards, and tries to escape the fortified Nazi stronghold Castle Wolfenstein, set during World War II. The game is often credited as one of the first video games of the stealth genre, since it focuses more on avoiding or disarming enemies, and killing them is considered a last resort.
Missile Command
Contemporary "Missile Command" clones include "Missile Defense" (1981) for the Apple II, "Stratos" (1982) for the TRS-80, "Repulsar" (1983) for the ZX Spectrum, and "Barrage" (1983) for the TI-99/4A. Silas Warner programmed the 1980 clone "ABM" for the Apple II several years before writing "Castle Wolfenstein". Similarly, John Field programmed the "Missile Command"-like game "ICBM" (1981), then went on to create "Axis Assassin", one of the first five games published by Electronic Arts.