In Circuit Keep, the intrusions walk straight over your towers. So you don't stop them with firepower — you carve their routes yourself. It's a maze tower defense game inside a living circuit lattice, with no fixed paths. INTRUSIONS breach from BREACH POINTS and pathfind toward your CORE across an open grid. You wall that grid into a killing maze with FIREWALLs , line the routes with damage, and force every wave down the path you chose. No preset routes to defend and no race against the clock — just a pure puzzle of position you can pause anytime to plan. PLACE. ROUTE. HOLD. Modules only fire when POWER reaches them, so you're not just placing damage — you're routing the grid that feeds it from the CORE and your CHARGE NODEs . Wall off the open lattice into the routes you choose, then decide which to harden and which to throttle. FOCUS FIRE Placement sets the trap; focus fire wins the moment. Mark any INTRUSION with a CROSSHAIR and every damage module in range promotes it to the top of its target list — concentrate the whole lattice on the threat that matters: a SCRAMBLER slowing your defenses, a BREAKER chewing through a FIREWALL . TWELVE MODULE FAMILIES. OPEN PALETTE. Damage comes in four flavors — KINETIC , THERMAL , ELECTRIC , CORRUPTIVE — and most modules layer on a STATUS EFFECT : THROTTLED slows a crowd, BURN melts a tank over time, EMP locks a target in a stutter-loop, and BITROT grinds down anything in sustained contact. Match your damage to the intrusion in front of you, or get shrugged off. Hold a route with the BARRIER families, slow crowds with JAMMING FIELDs , boost your damage with AMPLIFIERs , and broadcast POWER across the lattice from your CHARGE NODEs . Every module you've unlocked is on the palette every wave — pure strategy. PERSISTENT RESEARCH Clear levels with STARS to spend on a RESEARCH GRAPH that carries permanent upgrades across your whole campaign — extra CORE HP, faster CHARGE , cheaper module classes, BARRIER reinforcement. FEATURES No fixed paths. Intrusions walk over your modules; you carve the maze yourself with FIREWALLs . Branching upgrade paths. Every module has two paths leading to an L4 CAPSTONE that reshapes it — crit, knockback, pierce, and more. Switch builds on the fly. Swap a module to its other upgrade path mid-fight to answer whatever the wave throws at you — it keeps the upgrade level you already paid for. RECYCLE into OVERCHARGE. RECYCLE a module past your battery cap to overflow the lattice into a faster-firing power spike, exactly when you need it. ROUTERS bend the route. Ordered checkpoints intrusions must hit — heal stations, speed boosters, and GATEWAYs that drag the breach point forward. The lattice fights back. DRIFT CURRENTS shove intrusions off course; buildable TRAP CELLS sear them with STATUS EFFECTS as they cross. 12 module families. 12 intrusion families, 7 elites, 3 bosses. A three-act campaign, an escalating ENDLESS mode, and a persistent RESEARCH GRAPH . INTRUSIONS THAT FIGHT BACK These don't just walk toward your CORE and soak damage — each family forces a different answer: SCRAMBLER — broadcasts a field that slows the fire rate of every module near it. Stack a few and your rack barely cycles. PARASITE — ignores the CORE at first to hunt your CHARGE NODEs , latching on to siphon your income, then detaches and turns HARDENED for its run at the CORE . PHASE — slips intangibly straight through your BARRIERs on a cycle, beelining the CORE while your walls do nothing. HOPPER — vaults over a FIREWALL or a gap in the wires on a cooldown, landing on the far side mid-stride. BREAKER — a dedicated wall-chewer that takes your BARRIERs apart far faster than anything else, and shrugs off EMP . SWARM — a networked scout: the instant one finds a clear path to the CORE , the entire wave snaps to that route. SHARD — a crystalline shell that shatters into a cluster of SWARMs right where it dies. PHANTOM — cloaked and deflecting KINETIC fire; you have to slow it with THROTTLED before THERMAL can land a clean kill. SABOTEUR — a glass-cannon kamikaze immune to every STATUS EFFECT : drop it with raw damage before it reaches the CORE and detonates. Three bosses, three rule-changes — one clamps every hit to a single point of damage (win on fire rate), one locks out whichever module family is carrying the fight, and one forks off a new intrusion every cycle, faster as its own HP falls.
