The Cuniculus of Paradise

In the near future, humanity has achieved remarkable progress with the discovery of infinite energy called "Akasha Particles." However, this advancement also brought about the emergence of "Gigantic Beasts," which dethroned humans from the top of the ecological hierarchy. The survival of the displaced humans now depends on large humanoid weapons called "Exos" and the "Mercenaries" who pilot them. The protagonist, a former mercenary, lost the ability to use Akasha Particles due to a past accident. Unable to pilot an Exo, he considers himself a "defective" and wanders aimlessly, leading a reclu(Storyline via IGDB)