Though Galaxy Fight is similar to Sunsoft's later game Waku Waku 7 (which uses the same engine), the games have few elements in common (one of them being the mid-boss, Bonus-Kun). The players choose one of eight characters and travel among the in-game solar system to defeat the opponents inhabiting each of the planets before they get the chance to fight Felden and settle their personal scores with him.
The game uses a four-button layout where the first three buttons are used for striking attacks of varying speed and power (they can be anything ranging from punches and kicks to tail whips and bites). The fourth button is used specifically for taunts which has no practical impact. Combining several buttons together may yield new attacks or special moves depending on the character.
There are no walls in the stages to corner players; instead, the screen can scroll indefinitely.