The Stairway 7 is an endless loop anomaly hunt and observation "spot the difference" game where you are stuck in a endless loop of stairways with a cat and you have to observe your surroundings carefully to reach the exit. Anomalies are watching, and ready to hunt you down. Don't take them with you.
The core "spot the difference" mechanic requires you to meticulously scan each floor, searching for subtle changes in the environment. These anomalies can range from flickering lights and shadowy figures to more obvious alterations. When you identify an anomaly, you must go back down the stairs to remove it, or else risk taking damage.
In addition to the anomaly hunting, the game features a health system that adds tangible consequences to your actions. If you fail to spot an anomaly and continue up the stairs, you will take damage. You can replenish your health by finding medkits scattered throughout the environment. If your health is depleted, you will die and be sent back 10 floors, rather than restarting from the beginning.
As you ascend the increasingly twisted and ominous stairwell, you can also find notes and other items that provide narrative context and additional secrets. Managing your inventory and resources adds an extra layer of strategy to the gameplay.