Combat Machines is an action game in 3D. In this game, players assume the role of a combat machine commander who has been ambushed in an enemy territory. To survive, the player must use his or her weapons to destroy the enemies. The player must strive to stay alive until the rest of the team comes along and rescues him or her. There are various weapons available to the player, such as a machine gun and a flamethrower. The game is divided into different mission levels, with each succeeding level more challenging than the first.
Players can use the left mouse button to fire weapons. Players start with a tank as combat machine. Movement is controlled using the keyboard’s arrow keys. Players can switch to the next weapon in their arsenal by pressing the Pg Up key and switch back to the previous weapon using the Pg Dn key. To pause the game or return to the main menu, players can press the Esc key. Players can use a superweapon, activated using the space bar, when they are surrounded by enemies. Arrows on the game screen show the players which direction to go to accomplish their tasks and consequently their mission. Some of the tasks include going to the checkpoint where they must collect a briefcase, and killing all enemies using their weapons.