Labyrinth of the Castle (宮殿のラビリンス Kyūden no rabirinsu?) is the fourth and final Zone of Sonic Labyrinth. Like other Zones in Sonic Labyrinth, the Labyrinth of the Castle consists of four acts, with the three first being standard Zones while the fourth one is devoted to the local boss.
The Labyrinth of the Castle takes place inside a stone fortification at night, with the full moon hanging in the dark blue, star-dotted sky above. Only white candles lit up the walls. In terms of color schemes, the first Zone features a dark blue color scheme with light blue Conveyor Belts, the second features a purple color scheme with blue Conveyor Belts, the third Zone features an orange and green color scheme with river-like Conveyor Belts, and the fourth Zone features a dark blue color scheme again.
Having only the Labyrinth of the Castle left to explore in the Super Labyrinth during his hunt for the Chaos Emeralds, which he needs to remove the Speed Down Boots that he is currently wearing, Sonic infiltrates the labyrinth with only his Spin Dash to help him get around since the Speed Down Boots have robbed him of his speed and agility. Eventually, Sonic makes it to the end of the Labyrinth of the Castle where he has his showdown with Dr. Robotnik, who attacks him with his Smiley Bomb. After destroying it, Sonic recovers the Chaos Emerald the robot dropped. Shorting thereafter, Sonic comes after Dr. Robotnik, who flees from his base, dropping a Chaos Emerald along the way, which Sonic also recovers before exiting the base.
Like with all the Zones in Sonic Labyrinth, Sonic's objective in the majority of the Zones in the Labyrinth of the Castle is to collect three Keys and bring them to the goal within a certain time limit in order to advance to the next Zone.
In the Labyrinth of the Caste, there are many gimmicks and dangers derived from the past Zones in the game. The Zone is also much more difficult and complex that the previous three, being littered with bottomless pits that can reset Sonic's progress in a Zone if he makes a misaimed Spin Dash, and intertwining passageways. The first three Zones also have Conveyor Belts that can send Sonic off-course.
The individual Zones feature their own sets of gimmicks and obstacles. In Zone 4-1, Aroros perch on inaccessible slabs of terrain and flaming arrows fly hither and thither across the long corridors. There as well as well damage-inducing guillotines, will-o'-wisps that move around, retractable spikes in the form of spears, and flaming caterpillars that crawl aimlessly around on the floor. In Zone 4-2, the Conveyor Belts are longer and there are damage-inducing stalactites falling from above. There are also flashing blue puddles that can teleport Sonic to other sections of the Zones, much like the panels in the Labyrinth of the Factory, and the aforementioned flaming caterpillars. Lastly, in Zone 4-3, the Springs from the Labyrinth of the Sky for reaching higher floors make a reappearance, along with the aforementioned retractable spears and falling stalactites. In addition the Conveyor Belts flow and cascade across the different floors like waterfalls and connect them, making it tough to navigate the pathways without making an error that can set them significantly back.
In this Zone, the time limit starts off at one minute and thirty seconds.
In this Zone, the time limit starts off at two minutes and thirty seconds. This Zone features a number of confusing passages akin to those in the Labyrinth of the Sea. There is also a Key in this zone that is protected by orange balls. However, they can be turned off by pressing the hidden Switch on one of the balconies.
In this Zone, the time limit starts off at three minutes. This is by far the most complex Zone of them all.
When the player reaches the goal, the screen will pan up to a giant clock that is situated above the goal. If the player manages to get to the goal with all three Keys before the countdown goes below 2:00, the aforementioned clock will ring three times and release a flock of doves from inside it.
In this Zone, there is no time limit. When beginning this Zone, the player has to go down a slope with a large amount of Rings to collect, breakable clouds, and spikes along it. At the end, the player will enter a hole and pass through a chute that takes them to the boss fight with the Smiley Bomb. After defeating it and reclaiming the Chaos Emerald, the player will automatically move into the ending sequence of the game, followed by the credits.
The boss of the Labyrinth of the Castle is the Smiley Bomb, a floating robot bombarder. When beginning this fight, dodge the shower of bombs that rain down from above and the Smiley Bomb will appear. The Smiley Bomb itself hovers around above and attacks by flying over Sonic's position and dropping a bomb. The Smiley Bomb will then follow up on that by lowering itself and attacking its point of impact directly. This is where the Smiley Bomb can be attacked. After ten hits, the Smiley Bomb's lower half disappears, leaving only its head behind. The head attacks like before, except that instead of dropping a bomb, it spits out a laser that into two smaller beams when hitting the floor. Land ten more hits on it and the Smiley Bomb will be destroyed.
|N/A (Zone 4-1)||A. Iwanaga||2:02|
|N/A (Zone 4-2)||A. Iwanaga||2:02|
|N/A (Zone 4-3)||A. Iwanaga||1:51|
|N/A (Zone 4-4)||A. Iwanaga||1:13|