Subs

Subs is a shooter arcade game, that had been released by Atari in 1977; it utilizes a Motorola M6502 (running at 756 KHz), and both players must use a steering wheel to take controls for a submarine (in first-person) with a single button to fire torpedoes (but if there is only one player, the CPU will fill in for 2P). Neither player actually sees each other's submarine (except for on the sonar at the bottom-left of 1P's screen, and the bottom-right of 2P's, occasional fleeting glances, and where a torpedo is coming from) - and, whoever torpedoes his opponent the most times before the timer runs out wins the game. This game was also the first to feature multiple monitors, a concept which would later get adopted by: Nintendo for the "PlayChoice-10" cabinet in 1986 along with Taito Corporation for The Ninja Warriors in 1987, Sega for their "MegaTech" cabinet in 1989, Namco for Driver's Eyes in 1990 and Konami for their 6-player version of X-Men in 1992; many other companies went on to use multiple monitors, too.