Players control one of seven giant beasts and must fight to conquer a post-apocalyptic neo-Stone Age Earth (known as "Urth"). Like the large bosses in the early Mortal Kombat games (and the dinosaurs of Taito's Dino Rex), all beasts are rendered with stop-motion animation as model figures (while the small human followers are digitized actors). The game features numerous blood effects, including an end-of-round fatality system.
Along with major arcade revisions (adding new special moves and abilities), the game received numerous ports for home consoles and handhelds in 1995. Other than the SNES version (which was ported by Bitmasters) and the PC version (which was ported by Teeny Weeny), all ports were done by Probe. They were released in North America and Europe by Time Warner Interactive for the Sony PlayStation, Sega Saturn, Super Nintendo Entertainment System, Sega Genesis, Sega 32X, Game Boy, Game Gear, Jaguar CD (exclusively in North America), 3DO (exclusively in North America), Amiga (exclusively in Europe for ECS and AGA systems), and PC (released for MS-DOS in CD-ROM format). It was also released in Japan for the PS1 (on December 13, 1996 by Time Warner Interactive) and Saturn (on February 26, 1998 by GameBank).
Along with a short-lived toyline, it also received a four-issue comic book mini-series years after the game's original release. A sequel named Primal Rage II was in development in 1996, adding a new assortment of giant playable human "Avatars" (also rendered from model figures) to fight alongside the beasts. Although this sequel was canceled prior to release, some prototype boards from public tests (along with official cabinet artwork) of the sequel have been found, one of which is publically playable. Despite its cancellation, both games received an overarching novelization in 1997 (titled Primal Rage: The Avatars).
Primal Rage plays like a traditional 2D fighting game. Along with a joystick, each player has four buttons arranged in a square (horizontally from Quick to Fierce and vertically from High to Low). Pressing both High Quick and High Fierce simultaneously executes a powerful High Power attack, while pressing both Low Quick and Low Fierce simultaneously executes a powerful Low Power attack.
Unlike traditional fighting games, where special moves are executed by first moving the joystick in a combination and then pressing one or more buttons, Primal Rage includes a system where special moves are executed by holding down certain buttons and then moving the joystick. Glorified execution moves, known as Fatalities, can also be performed this way at the end of the winning round. However, later arcade versions and most ports also include the traditional special move/fatality execution alongside this way.
During the fight, human worshipers from the tribes of both fighters are scattered in the background. All characters have a special move (with unique combinations) which allows them to devour humans that enter the foreground, giving back some of their vitality. Devouring enemy worshipers also grant the player bonus points, while devouring friendly worshipers take away from the player's score.
After defeating all seven opponents In the single-player campaign, the player has dominated Urth. But the beast still needs to prepare for one giant final endurance round to keep their place as "king of the hill". A bonus round occurs where the player has a limited amount of time to devour friendly worshipers (with no point loss) and flying pterodactyls for bonus health (that is used after the player's health has depleted in the final battle). During the final battle in the hellish "dinosaur graveyard", the player must survive against all seven opponents consecutively in one giant round. If the player loses both the initial health and the bonus health, they can immediately restore their character's initial health by continuing. The player is granted more points at the end of the campaign by using less continues.
The game includes seven playable beasts (six in the Game Boy and Game Gear versions). A final boss beast was planned for the final stage, but was scrapped and turned into an endurance match against the entire roster.
Sauron and Blizzard are palette swaps of Diablo and Chaos. However, both Diablo and Chaos are smaller in size.