The hook is that dying inside the building only resets you, so the building reads as an almost infinite resource you return to again and again. That single rule is what justifies a roguelite structure in-world: people keep going back because the building keeps letting them.

Each run is about climbing as high as you can (enter, scavenge upward, survive, push or die, wake outside), with most things resetting between runs and a few specific items carrying over. Layered on top is the infection clock: take a bite and a countdown starts, turning a careful climb into a race where you gamble the remaining time for more loot and height, or get out while you can.

Emilia Ritz is the single body you carry through every run, the one constant while the building resets around her. Under the hood she's a composite of six independent sprite layers (arms, legs, torso, head, gun), so costumes, weapons, and re-skins all have somewhere to plug in. Enemies are built the same way, keeping the layered system consistent across the whole project.

Most threats are ordinary zombies, but the standout is the Grabber, a zombie whose whole job is to pin you in place so the others can close in, exploiting the loose, movement-based aiming. It sets the survival-horror tempo: deliberate, not fast (avoid and conserve rather than clear every room), with the roguelite climb pulling you forward over the long run.