In the style of Mortal Kombat or Street Fighter, a player can play against another human opponent or computer-controlled opponents in different levels using hand-to-hand combat, special moves and weapons to defeat each other. A distinct feature in Battle Beast is the use of animals, which can transform into large robotic machines to battle one another. Players can select 6 different animals, which start off as cutesy-looking pets but all transform into large robots to fight, each animal has its own specific special combat techniques, weapons and attributes.
Players can fight on various different levels in the single player mode as they advance through "sewers" to reach the final boss, a large Toad (Toadman), and complete the game. There are also several mini-games mixed in between the fights such as races through mazes and secret bonus rooms to collect upgrades and weapons.
Multiplayer can be direct human to human combat, with two players battling each other on the same computer or across a LAN network or the internet. Players can also battle in a cooperative mode together, where two players can progress through the single player levels together.
The game's main menu describes in the single player mode, the evil Toadman's latest crimes committed by his henchmen, upon unnamed cities. The Toadman begins to infest cities with his swarms of toads that ravage havoc upon the inhabitants. The storyline is introduced to the character with very comical and humorous cartoon clips, set in cities, that usually end with someone being eaten by the toads.
The player starts by choosing a "Battle Beast" and travels through sewers, fighting other Battle Beasts, which can be controlled by the computer, or another human player in the head-to-head versus mode. After the travels to each different battle ground in the unnamed city, via the sewers; they are brought to a final level where they face the Toadman himself. Once the Toadman is defeated the player wins the game.
Game play revolves around two combatants battling it out on varied levels. Each combatant can change from animal form to Battle Beast form at any time during the battle. Powerful special moves and combinations can be performed by pressing several keys in sequence, much like other various fighting games. While players start off as animals and in the animal form players can pick up various powerups and items, most of the fighting is done in the "Battle Beast" form . Each level contains some hazards and special traps, and can also contain secret entrances and passages the player can enter which will lead them to "powerup" rooms which give them weapons or a maze to find a special item. Some items spawned during levels can be helpful, while others damage players.