Golf Party IO is an online multiplayer skill-based sports game based on mini golf and putt-putt. The player must pot their ball in a hole under a flag as quickly as possible in a wide range of environments to rank high on a global leaderboard. They must also complete this task in as few shots as possible.
The game doesn't supply the player with a putter in the teeing area. Instead, they must use swiping motions to direct the ball toward the flag and hole. Each course features a variety of obstacles and traps, including inclines and ramps, cliffs and drop-offs with chasms between areas, turnstile sections of track, windmills with moving blades, and theme-based objects that form dead ends.
Golf Party IO provides the player with a white targeting line that looks like a swoosh of air. The swoosh turns red if the player overcharges the shot. The game also allows the player to switch the camera view. That said, any change can cause the player to lose their shot orientation, which results in them hitting the ball in the wrong direction. The targeting line helps them reorient quickly.
The player can join a random room via the Quick Play mode. They can also join a room with an invitation code or create their own room. While they wait for others to complete a round, they watch the game in Spectator View.