Astrolab

"This is where most of the experiments to find a cure... failed."

The Astrolab is a special level accessible after the Throne Room only when playing with 5 Boss Stem Cells active.

The Astrolab is the main laboratory used by the Alchemist for his experiments with curing the Malaise. This biome is particular in that it consists of a succession of floating platforms and structures with ladders connecting them, which the Beheaded must climb to reach the exit leading to the Observatory. If the player falls in the gap between platforms, they drop down far below and take a lot of damage.

On the walls of the Astrolab rooms, one can see scientific drawings and schemes alluding to the Alchemist's experiments with the Malaise and Cells, as well as plans to brew the Panacea.

In order to reach the exit, the Beheaded needs to collect a series of keys by beating Elite enemies. An Elite Failed Experiment and an Elite Slammer drop the Elevator and Allen keys, respectively, which can be used to reach a room where two Elite Slammers are waiting. Upon defeating them, the player finds two Guardian's keys, which open the doors to the Observatory.

The Astrolab is home to two unique enemies that cannot be found in any other location of the island: the Magistrate of Death and the Defender. Those two enemies carry exclusive blueprints, respectively for the weapon Hemorrhage and the shield Thunder Shield. In addition, a hidden tower (usually located in the bottom center of the map) contains the Apex key behind a series of traps, which can be used to retrieve the blueprint for the Sonic Crossbow (see Gallery)

Loading screen quotes

 * "This is where most of the experiments to find a cure... failed."
 * "Some test subjects are still roaming this part of the island. This is why the King ordered the main gate closed."
 * "Experiment number 463 was horrible! Number 464 will blow your mind!"
 * "No animals were harmed while researching for a cure against the Malaise, promise."