When the player begins playing Babel no Tou, they are given the ability to select any one of the 64 floors to start on. However, every floor beyond floor 15 requires a password to access. Passwords for floor 16 and beyond are provided just before the player begins a particular floor after successfully completing the previous floor. Each password is composed of four tiles of four particular images: a wall tile, an L block, a vine tile, and a door.
After a floor is successfully exited, a point tally is presented, showing how many points the player receives for a number of considerations; the floor difficulty, the strength remaining, and the number of bonus items collected throughout the floor. These points are added up and combined with the player's total score. Score has particularly little effect on the game itself.
The player will begin each new game (whether starting on the first floor, or continuing from any other) with three lives. An extra life is earned upon successful completion of each floor. When the player runs out of lives, the game is over. However, the player may choose to continue on the floor that the player died on, provided he or she knows the password required to start the level if the floor is higher than 15.
Every eight floors, the player is presented with what appears to be a rather simple floor compared to those previously encountered. In truth, the goal on these floors has less to do with successfully reaching the exit, and more to do with finding a way to reveal the hidden symbol that can appear in the room. This usually involves holding some combination of controls under certain conditions until the symbol appears. Once you reveal the symbol, take note of it, as it is the key to determining the correct solution to the Big Password puzzle that you are presented with after completing floor 64. Without entering the Big Password, which is composed of 8 somewhat random symbols, Indy will not be able to lay eyes on the secret Air Garden of Babylon. Don't dismiss every eight floor as a simple break from hard thinking. Find a way to reveal those symbols! The walkthrough will provide the methods in a spoiler section if you can't figure it out.