In Entwined, the player has to control two souls to lead them to perfect harmony.
The main protagonists are the souls of an orange fish and a blue bird. They fall in love, but due to their incompatible environments, they can't stay together. However, if they become so entwined that they learn to move in complete unison, they can merge into a dragon. This creature can traverse any environment.
The player takes control of both protagonists at the same time. Being a PlayStation exclusive title, Entwined strongly relies on the console's controller analog sticks. With the right stick, the player guides the bird, while the left stick navigates the fish.
The two protagonists fly forward through a tube, similar to the old flight simulators like Tempest 2000. On their way, they have to gather collectible gems and avoid obstacles. The collectibles are color-coded orange and blue for the fish and the bird, respectively. Completing these objectives allows the player to fill two colored meters while hitting obstacles drops the meters down. Once they are full, the two souls begin to merge. They have to avoid being hit during the merger process. Otherwise, it will be interrupted. When the fusion is complete, the two characters become a dragon. The player can control the dragon and freely explore the final part of each stage, which turns into a 3D environment.