Central to Until I Have You is the exoskeleton suit. The suit gives the player special abilities at the cost of the player's sanity. The exoskeleton comes with the abilities to slow down time, ala Max Payne and to rewind time. However, overuse of these abilities will cause the sanity bar to deplete making your character lose touch with reality. When the sanity bar depletes your character starts to hallucinate, altering gameplay mechanics and level design.
In each stage, the player navigates his way from left to right through platforming sections, death traps, and enemies. The goal is to do this as fast as possible with the least amount of deaths. The fast pace of the game can make it difficult to plan a perfect approach. To make up for this, the game allows the player to restart each stage the moment they die, allowing them to quickly fine-tune their approach over several attempts. At the end of each chapter the player must also defeat a unique boss. Along the way the player acquires a number of weapons and upgrades that you can cycle through, all of which have a specific use.
The game grades the player's performance at the end of each stage based on a number of factors and given a percentage raring out of 100. Things you get judged on include method of death, whether you kill any of the enemies and what you killed them with.