Altered Beast is a side-scrolling action game in which your character, recently revived from the dead, is sent to rescue the kidnapped daughter of a wizard. Unarmed and alone, your warrior must batter his way through five levels of misshapen enemies to force a confrontation with the rhino-headed final boss. In each level, you must obtain three power-up orbs. The first two simply make your character larger and stronger, while the third transforms him into anthropomorphic animal with tremendous power.

Level design is simple, with minimal terrain; just the occasional upper tier to jump to, and here and there breakable rocks and tombstones to impede your progress. The focus of the game is not platforms and jump puzzles, but fighting, pure and simple. There are no directions to choose as you progress through a level, only more bad guys to pound on.

Controls consist of a standard joystick and three buttons: jump, punch, and kick. Pointing the joystick left or right as you jump will propel you in that direction, while pointing it upwards with jump will give you a special high jump. (The high jump can carry you onto an upper tier. Once on a tier, you can only drop back down when you find the edge.)

The punch is a high attack and the kick is a low attack, and each is appropriate to certain enemies. Pulling the joystick down makes the character crouch, changing the punch to a low hit and the kick to an upward strike (good against aerial enemies). Attacks can also be performed while jumping, and again, this is appropriate for certain enemies.

When the character powers up to one of the four available beast forms, the basic attacks change. Each beast has its own set of powers, but they are consistent in one way: they carve through the regular enemies with ease. Once beast form is achieved, however, it is only a matter of time before the level boss comes for you, and there you will again find a challenge. Once you defeat the level boss, you are powered down to your base form before the new level begins.

You start the game with two to four men, depending on the dipswitch settings, and a life gauge that measures the damage you've taken. Naturally, when the gauge runs dry you lose a life, and your new man is dropped into the level right where you left off. You can also lose a life by falling into a pit, but these are very rare. You can continue the game so long as you have quarters, and two players can challenge the game simultaneously. ~ Michael W. Dean, All Game Guide