Mystery Tower, previously known as The Tower of Babel (Babel no Tou) or just Babel, is an action puzzle game. The game consists of 64 "floors" or puzzles that involve the positioning of many L-shaped blocks. You must manipulate them to create stairs so you can reach the exit of each floor. Some floors are sealed, and you must collect crystal balls to escape. There are items to collect for bonus points, and a small number of enemies to avoid.

The game was a Japan-exclusive title up until its release on the Nintendo Switch Online service, finally receiving its current overseas title.

In the beginning, an archaeologist and explorer known as Indiana Borgnine is in search of the fabled Hanging Gardens of Babylon. After reading some lost scriptures, he determines that the only way to see them is to travel to the very top of the 64-story Tower of Babel. Upon reaching the Tower, he discovers that the only way to access the floors above him are to solve some challenging puzzles involving loose L-shaped blocks that he finds throughout the Tower. To his great surprise, the blocks are capable of balancing very well on top of one another, in order to form staircases.