Clockwork Citadel

What it is

Rust bugs crawl toward the heart of an old 24-hour clock tower. Three rings guard it, and you bolt parts onto them (cannon, shield, coil, amplifier). The center cannon aims on its own, but ring parts only face outward, so you drag the rings by hand to aim them.

The hook: alignment combos

When parts on different rings line up, they link up: cannon + amp = Overcharge, cannon + coil = shock shells, shield + coil = arc barrier... and there's a secret one when all three rings line up.

Other features

A 24-hour day cycle: spawns peak at noon, when a boss shows up Inner rings are tougher, and when the inner ring breaks, the clock stops Real-time research lab, plus a prestige layer ("Change clock") after Day 10