The Hazardous Ruins are dangerous ruins located northeast of Portia in the Collapsed Wasteland. The Hazardous Ruins is home to dangerous enemies and traps, causing the ruins to be strictly prohibited from trespassing. The Civil Corps are responsible for closing off the entrance to the ruins. By proving the player's strength by sparring with a Civil Corps member, the player can enter the Collapse Wasteland and enter the Hazardous Ruins.
Entering the ruins consumes a certain amount of time, although time inside the ruins freezes. Each time the player enters another level, time is consumed. Time is not consumed when advancing to the next floor, however. Advancing to the next floor requires meeting one of two criteria: simply navigating through obstacles or defeating all enemies in the floor. The player has the option to quit in the middle of a run to return to the overworld.
Levels 3 & 4 introduce a timed element to the layers. Extra time will be added to the clock for monsters killed and boxes smashed.
The Sewage Plant is a toxic ruins home to poisonous enemies and the Chemical Dropout.
The boss on each level is a Chemical Dropout. The boss is level 17 on floor 1 and level 19 on floor 2.
At any point in time you can leave the ruins without finishing the specific level without having to worry about losing it.