As in the previous games of the series, in Fireboy And Watergirl 4 you control Fireboy with arrow keys and Watergirl with WASD and you should set them away from their rivaling elements. Watergirl, for instance, must not take a lava bath, although Fireboy can pass through it fine, and the both heroes need to get rid of the green acid. When either of them dies, you need to begin the level from the start. At this point of time, however, you see yourself in a temple where portals available everywhere. Every portal sets in the gem frame and connects to other similar frame on the level, however few portals have distinct destinations based on what side you are entering, hence keep in mind that white glow matches white, black to black so long the gem colors correspond.