AntCity is a take on the classic pastime of small kids using magnifying glasses to burn ants. The player takes the control of a giant who has gotten a hold of a giant magnifying glass and now looks at the humans below as tiny ants. The goal of the game as well as the controls are simple: set people, cars and trees on fire.

Players can hit roaming people, trees, cars and the occasional helicopter, causing the vehicles to crash and setting people ablaze. Players use the mouse to move around the magnifying glass and press and hold the left mouse button to intensify the beam to burn various objects.

The end of the game comes when a passing tanker truck comes onto the screen. Then the player can choose to either continue burning other people or set the tanker on fire, causing it to explode and leave a massive crater in the middle of the city, ending the game. There is no score keeping system or any difficulty or mode settings.