Clockwork Keep

Clockwork Keep is a tower defence set in a brass-and-copper workshop lit by oil lamps. A riveted iron walkway runs through cobbled yards, over giant gears sunk into the floor and past steam vents that cough on the half minute, and it ends at the gate of a clock tower whose glowing face you are paid to protect. Hexagonal brass pads sit along the walk, and what you bolt onto them decides how far the intruders get.

Five contraptions, three tiers each. The steam cannon lobs a splash shell that knocks the light ones back down the walk. The tesla coil throws lightning that jumps between up to five targets and leaves wind-ups twitching. The gear launcher throws fast cogs that ricochet into a second target. The pressure valve is a grate set into the walkway that scalds and slows everything crossing it, and at tier three it shoves the whole crowd back a step every few seconds. The automaton foundry builds two brass workers who stand in the road, block what comes and hammer their own dents out between fights. Every one of them has an overclock lever: eight seconds at double rate, then fifteen seconds of cooling while the gauge on its pad crawls back down.

Wind-up spiders swarm, brass beetles shrug off knock-back, key soldiers keep marching for three seconds after their spring runs out, zeppelins float over the ground guns and drop more spiders, piston crabs flatten an automaton in a single blow, and oil slugs leave slicks that make the next tesla bolt spread twice as far. Every fifth wave a brass colossus walks in — a boiler on legs that only the coils can overload, and every stagger vents another pack of spiders. Steam pressure builds as you break things and can be vented to slow the entire yard, ground gears can be reversed with a tap so they fight the intruders instead of carrying them, and there are three stars on every one of the twelve yards for a defence that never lets a single cog through the gate.