In Heart of Metal, two players have to control one robot together, and the robot is in two parts. One player plays as a Gunner to shoot the enemy. Another is a pilot who controls the movement of the robot. The gunner and the pilot must work together to defeat their enemies. The Pilot tells the gunner about the enemy location and when to dodge enemy bullets. And the Gunner can tell the pilot where the target is.There are 6 different mecha body parts in the game, player can choose any one of them and combine with their teammate to join the game. You can use complex strategies by choosing various skills before entering the game. There are 5 skill trees in the game. By using different skills, you can choose to attack aggressively with your teammate or use “detach” skills to fight alone. You can get different powerups, equipment, and weapons in the game. Use different items will give you advantages or even help you win the game. Be careful, your enemy also can pick up those items.