Giant Fish Survival: I Can Hear the Giant Fish's Heart

[No system + no female lead + minimal cheat codes + farming + character development + slow-burn survival + not a saint but with human touch.] All of humanity is transported to a strange ocean world, living within the stomach of a giant fish called the Leviathan. Humans must help the Leviathan clear harmful creatures from its stomach, and in return, the Leviathan will find supply boxes to aid their development. The creatures in this ocean world are all exceptionally large; even the parasites are far larger than humans. Humans must constantly acquire supply boxes, upgrade their abilities and equipment, and fight against the creatures invading the Leviathan's stomach. While everyone struggles...