Metal Gear Ac!d

Metal Gear Ac!d is a spin-off from the main saga that studio Konami Computer Entertainment Japan prepared for the PSP handheld in 2004 as one of the console's launch titles. Instead of real-time stealth, it offers turn-based strategy built around a deck of cards — each card represents a weapon, an item, movement, or a special ability, and the player builds their own deck before each mission from cards collected during play and purchases between missions. The story takes place outside the series' numbered continuity and follows an agent named Snake caught up in a conspiracy involving a bioterrorist attack on a research center, so the title can be seen as a standalone experiment with the brand rather than canon for the main line. That's also why the game works with its own set of characters and factions that don't otherwise appear in the numbered entries.

The combat system combines movement on a square grid with a limited number of action points per turn and cards that need to be efficiently chained into sequences — the silent progression of the classic entries is thus replaced by turn planning and guessing which card the opponent will play. Cards are divided into attack, movement, support, and so-called instant cards, which can be played out of turn as a reaction to the opponent's move, giving the game an element of bluffing as well. Visually, the game relies on simple isometric 3D environments and, between missions, on striking comic-style cutscenes drawn by Ashley Wood, which give the story a completely different tone from the console entries' cinematic sequences. Difficulty rises mainly through deck building and upgrading rather than the player's reflexes, so the game rewards patient planning over quick reactions.

Why play it: Ac!d will appeal to players who enjoy turn-based deckbuilding card strategies and are also curious how far an established action brand can be reworked into a completely different genre. It's a curiosity from the PSP's launch period that will appeal more to fans of unconventional spin-offs and card tactics than to those expecting classic stealth missions of sneaking past patrols from the Metal Gear name.