This map consists of rusted platforms, carpets, holes, doors, and boxes. A major part of the gameplay is swimming in acid to press buttons, or venturing through the map. This test map is challenging with many hard jumps, although it is repetitive throughout. You would wait for your air to rise, then loop or go down to get through. Most players would fail at the dives because of waiting for the button to be pressed. The map Old Apartment still does have the trend of most insane of "Fall and you fail" jumps, and that rule only applies to the actual jumps. This is also the only map with carpets as platforms. Many players rate this map as a harder insane.
Walkthrough and OST