Metal Gear Acid

Metal Gear Acid is a non-canon, portable edition of the famous Metal Gear series of video games. Unlike other Metal Gear games which are primarily stealth action genre games, Acid is a turn-based collectible card game, requiring of the player strategy more than reflexes. The game was developed and published by Konami Computer Entertainment and was released on March 22, 2005, for the Playstation Portable console.

A retired Solid Snake is called back into service to combat a group of terrorists who hijack a plane and capture Senator Hach, an important politician. The terrorists had demanded Pythagoras, a research project in the Moloni Republic in Africa. Solid Snake must infiltrate a Moloni laboratory to uncover information about Pythagoras and the terrorists.

Metal Gear Acid's gameplay is very different from that of any other Metal Gear game. The game is a collectible card game executed in a turn-based strategy format. Solid Snake and others' actions are limited by his deck of cards, which can be revised and expanded upon as the game goes on. The game challenges the player to optimize their deck and then use their cards tactically to the best of their ability in battle.