Questprobe featuring The Hulk is a graphic adventure game in which the player controls the Hulk and his human alter ego Bruce Banner. The player can move between locations within the game's environment by entering one of four directions (north, south, east, and west), and can examine objects in search for clues to advance the narrative. The game features a 120-word vocabulary, and the parser can only register commands up to two words in length, generally in a verb/noun format (for example, "open box"). Commands consisting of a single letter may also by entered to expedite gameplay time (for example, "u" or "d" to move up or down). Although lethal scenarios may be encountered, dying merely results in the player being deposited in a limbo-like room, where the player may enter "go down" to descend a flight of stairs and resume gameplay without penalty. The game's graphics can be toggled on or off. The player can save their progress by entering "save game" and assigning the current game to one of four code letters (A, B, C, or D), which can be entered to load the game at a later time.

Bruce Banner awakens to find himself bound to a chair in a mysterious chamber. He manages to transform into the Hulk and free himself, but gas fills the room and permeates his skin, reverting him back to Banner. He explores his surroundings, which consist of three dome-shaped buildings and a grassy field surrounding them; Banner is able to transform into the Hulk outside of the domes. He happens upon an astral projection of Doctor Strange, who advises remembering Nightmare and encourages him to "look for Scott's next Marvel Adventure at [his] favorite store" before vanishing. In a cavern, the Hulk encounters Ultron, who has trapped Ant-Man in a cage. The Hulk gathers a swarm of army ants from the field, allowing Ant-Man to control them, incapacitate Ultron, and free himself. Throughout his exploration, the Hulk amasses a collection of gems. Upon retrieving all of them, the Hulk is approached by the Chief Examiner, who leaves him with the password "Aria".