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.
Castle of Riddles
Castle of Riddles is a text adventure released by Acornsoft for the BBC Micro (in 1982) and Acorn Electron (1984) home computers. The game was written by Peter Killworth and was one of a series of text adventures written for, or ported to the BBC Micro by the same author (others including "Countdown to Doom" and "Philosopher's Quest"). As with all such games, only text is used. The player must use a simple 'verb-noun' format (e.g. 'Go North', 'Get lamp') to control the game. Unlike Killworth's other Acornsoft adventures, "Castle of Riddles" was not updated and reissued by Topologika so became unavailable after 1985 when Acorn Computers (parent company of Acornsoft) pulled out of the games publishing market. Some of the puzzles however were included in the Topologika version of "Philosopher's Quest".