[Gameplay]
Biomutant is an action role-playing game set in an open world environment and played from a third-person perspective in which the player takes control of a mammalian warrior in a world filled with mutated animals. Players first customize their character including gender, length, body shape and thickness, fur, fangs, and many other attributes that can be tweaked and all have direct impact on the statistics of the playable character during gameplay. A thicker character is heavier, which makes it slower but on the flip side allows it to deal and resist more damage. The combat system combines melee attacks with long-range shooting. The player collects parts throughout the game and combines these parts to create a weapon. Each part has its own effect on the statistics of the end product. The game features a variety of Affixes, including cryogenic and electrical, which are effective in battles. When a cryogenic part is put onto a weapon, enemies will freeze when hit. The player can combine the power of multiple weapons by switching between different weapons during combat. The protagonist is able to dodge to the left, right, and backward, as well as jump. Besides leveling up the playable character, the player can also use level up points to strengthen their attributes or to unlock new attack combinations. Another way to learn new moves is by interacting with specific characters in each area. Most moves are based on weapons, which can be crafted using the game's weapon crafting system.

Throughout the game, players can also change their abilities, looks by mutations and bio-mechanical body parts such as attaching robotic legs, wings and claws which can be used to get various advantages against certain enemies or at certain locations. In order to reach specific areas, the player must change body parts, equip gear that is suited for that area, or obtain specific vehicles, such as an air balloon or jet skis. This way, the player can overcome obstacles introduced by their surroundings, such as the limited oxygen availability in Death Zone: by wearing a gas mask or an oxygen container, the player is able to venture deeper into the area and explore new places that cannot be reached without any precautions, while an even bigger part of the area can be reached by obtaining a mech. The game's world can be seamlessly explored by the player on foot, by flying or using an air balloon, jet ski and mech. It also features a dynamic weather system and day-night cycle which affect the gameplay and enemy behavior.

The story is mission-based and mission lines are character-based. Certain characters will provide the player quest lines that are emanating from their area. The more the player interacts with this character, the wider the arc of that specific area becomes.

Biomutant also features a Karma system for non-playable characters and a companion system for recruiting allies for fighting and travelling alongside the player. Depending on the actions, interactions, and decisions made by the player throughout the whole game, the stances characters take can change, which has an influence on the continuation of the story as dialogues and quest lines will be changed. The story is fully narrated. As playtime increases, the narration level scales down. Players will also be able to manually adjust the narration frequency.