Shoot 'em ups are a sub-genre of action games. There is no consensus as to which design elements compose a shoot 'em up; some restrict the definition to games featuring spacecraft and certain types of character movement, while others allow a broader definition including characters on foot and a variety of perspectives.

An action game is a video game genre that emphasizes physical challenges, including hand–eye coordination and reaction time. The genre includes a large variety of sub-genres, such as fighting games, beat 'em ups, shooter games, rhythm games and platform games. Multiplayer online battle arena and some real-time strategy games are also considered action games.