The race course features a long hallway with multiple doors (more appear in quicker succesion on subsequent laps), followed by a branching path (go left the first lap, right the second, and left the third). To win, you'll need to complete three laps in under the time limit, which means you'll need to be constantly looking out for which panels to open or close. You'll need to use those same controls to override many of the gates during the race.
As the Riddler drones on about the many rules you'll have to follow, you can either listen to all of them, or just press the prompt to hack the controls opening the gate. Whether or not you decide to follow up on the Riddler sighting early in the game, Mental Blocked is a Riddler-themed race track.
