GigaBash is a brawler game developed and published by Malaysian independent studio Passion Republic Games. It was released for Microsoft Windows, PlayStation 4 and PlayStation 5 on August 5, 2022. It was also released for Nintendo Switch, Xbox One and Xbox Series X/S on August 4, 2023. The video game centers on battles themed around the kaiju genre, and features crossover collaborations with characters from the franchises of Godzilla, Ultraman, and Gamera.

GigaBash is a brawler in which players assumes control of "titans" (giant kaiju, mechas, and aliens of various forms) to battle each other in stages filled with destructible environments, some of which involve hazards or otherwise disruptive (or helpful) elements like lava, flash floods with debris, spiked walls, avalanches, pitfalls, freezing water, non-playable enemy units, sandstorms, harmful intermittent energy pulses, massive collapsible buildings, explosive tanks, rideable missiles, or temporary boosts that can aid any of the combatants.

Each monster has a basic (light) and special (heavy) attack, which can be repeated, prolonged, or charged by tapping or holding down the associated button. Each titan is also capable of grabbing (with the grabbed object or enemy being thrown if the grab button is pressed again). All basic attacks (and some special attacks) change when done in the air or with a grab, while grabbing an enemy in the air results in a unique move that gains more points than even a triple combo. Combatants grabbing each other at the same time must mash the attack button in order to successfully grab their opponent, with a stalemate resulting in both combatants simply pushing each other away harmlessly. Certain combatants with beam attacks can also engage in a "beam clash", which involves mashing the special attack button to push the collision point between two beams towards the enemy before an explosion occurs and damages those closest to the collision point.

The monsters also have the ability to block (which can be disrupted by enough attacks, grabs, grab-based attacks, and explosions) and dash (backward when stationary, influenced by the direction the player is going in if mobile). Blocking can be done at the same time as a basic move (usually resulting in a parry, counter, deflective barrier, or omnidirectional attack) or a special move (which triggers an anti-air attack like an uppercut or an upward shot), and the dash can be combined with the basic attack for a forward dash attack, or can be done in the air for a quick, non-dashing dodge. Some of the characters have special gimmicks unique to them. Certain attacks, objects, and environmental hazards can also inflict status effects (most - but not all - of which bypass blocking) like burning (does damage over time), poisoning (slows and damages over time), restraining, freezing, dizziness, impalement, and electrocution (paralysis, with the last of the five sometimes erratically disrupting movement for a few seconds afterward), bleeding (does damage every time the inflicted character moves), and confusion (reverses controls).

The game revolves around Giga-energy, which may be found as orbs in certain places within some stages. However, Giga-energy is usually gained every time a kaiju damages their opponent (with some special moves gaining more by sacrificing health, knocking the enemy's Giga-energy out of them, or outright absorbing the enemy's Giga-energy). Once full of Giga-energy (as indicated by a pink meter), kaiju can transform into their significantly stronger and larger "S-class" state. This form is temporary, with the Giga-energy meter slowly depleting over time, but, although Giga-energy found in the environment cannot refill the meter while the monster is in its S-class state, the kaiju can fill their meter back up by doing combos or absorbing the enemy's Giga-energy with certain attacks. When a match goes on for long enough, a destructible bubble-like "Giga-ball" will start floating around the stage, which would allow any kaiju that shatters it to unleash an ultimate attack that deals devastating damage to other opponents. Titans can also steal the ultimate move ability from the enemy that currently has it by attacking them enough times before they can unleash it.

The game comes with four story modes where the player controls one of the four playable monsters. On March 26, 2026, a fifth story mode was added via DLC.

The game also has an arcade mode, where the player runs through a gauntlet of the game's nine original titan (excluding the player's monster) at launch, as well as both local and online multiplayer. In Onslaught mode, one or two players can fight through 50 waves of enemies (Classic), or 30 waves of enemies with powerful abilities (Mutants). In battle mode, players can engage in free-for-all battle, or split into 2 - 3 teams and combat each other. While the game supports up to four players, solo players can also compete against characters controlled by artificial intelligence. Furthermore, the game features "Mayhem mode", a party mode in which players can complete various minigames together.

The game's ten original monsters can be leveled up to 20 the more they are played. Leveling up unlocks a monster's skins and lore documents. The game's DLC characters have all their alternate skins and lore unlocked.