Milon's Secret Castle

The player controls Milon by running, jumping and shooting bubbles. The player starts out at the bottom floor of a four-story castle, named Castle Garland, and he must work his way upward, searching the three main stories, the well, two side towers and the very top. If the player stays too long outside of the castle, lightning bolts fall off from the sky. Each room of the castle contains many enemies and hidden items. Milon's bubbles are both a weapon as well as a tool; throwing bubbles at soft blocks causes them to break apart and either create additional routes, reveal hidden shops, or expose specific items. The bubbles can also destroy the demons that inhabit the given rooms, although they will come back to life after several seconds. Each story can only be reached by defeating the first boss. Although seemingly basic, the only way the bosses can even be reached is by discovering a host of secrets, some of which require sheer luck or a helpful manual. This is because there is no visual difference between these "soft blocks" hiding the secrets and the "hard blocks" which are just walls. When a demon-monster dies, it stays dead and releases a crystal ball and, at times, make Milon's bubbles larger and make them fly out farther. The demon-monster's room can then be used to get to the next story of the castle. Throughout the entire game the player is only given one life. When one life is lost, the game is over and the player must start over. If the player holds left on the control pad while pressing the Start button at the title screen, they can start where they left off. This command does not work before collecting the first crystal ball.^[2]

Along the way, Milon will come across various items found in shops; some shops are in plain sight, some are hidden in the differing rooms or outside the castle, and some can be found after Milon defeats a certain demon-monster boss. All of the items augment Milon in one specific way or another, although not all of them are found in shops.

Screenshot of the NES/Famicom version of Milon's Secret Castle

The game has generally been considered by several gamers to be extremely difficult and frustrating. There are no save points, and once a player runs out of life, the game is over, but it is possible to continue after obtaining the first crystal. Unlike in most platform games of the era, Milon does not "blink" to become briefly invincible when he is attacked by an enemy, which means his energy can be sapped very quickly if he does not move away. This is offset by the fact that each room in the castle has a "honeycomb" which restores the player's life bar entirely and extends it by one unit.

The game has a rather unorthodox approach when compared to other 2D platformers; the rooms can be accessed in any order, and the rooms themselves do not flow like traditional platformer stages. In each room, there is only one single exit, which is in a fixed spot within the room. Navigating a castle's room does not always require simply running from left to right, which gives each room a free-flowing feel. Each room of the castle contains secrets similar to those of the Super Mario Bros. series; the secrets are uncovered by shooting bubbles into invisible trigger objects and breaking soft blocks.^[3]