Some sections of floor inside are cracked and unstable, so a Mach Bike, which can quickly ride over the weak points before they crumble away, is required to reach the top. After one of the Fossils is taken, the tower will collapse, the remaining Fossil will sink into the sand, and the tower will never return. However, this other Fossil can later be found in the Desert Underpass, the entrance to which is located on Route 114 at the back of the Fossil Maniac's house, though it cannot be accessed until the player completes the game and obtains the National Pokédex.
There is a minor error on the second floor above the steps; it shows no rock but the player cannot walk there.
Mirage Tower may be inspired by a tower with the same English name that appears in Final Fantasy for the NES. Both towers appear in a desert, are only visible under certain circumstances, and contain a spiral-shaped interior.