How to play Core Defender

Core Defender is a tower defence game with no path drawn on the board, because you draw it. Corrupted packets stream from the entry port towards your core along the shortest route they can find, and your towers are the only walls on the board.

The rule that changes everything

Because packets always take the shortest open route, every tower you place rewrites their journey.

This is a maze-building game wearing tower-defence clothes. A wall in the right place is worth more damage than the tower on top of it will ever deal, because doubling the length of the path doubles the time every packet spends being shot at.

Placements that would seal the port off completely are rejected outright with PATH BLOCKED — you can never trap a packet with nowhere to go. That guarantee is what makes the maze safe to experiment with: you cannot accidentally break the level, so the only question is whether your maze is long enough.

The four towers, one by one

Pulse handles single targets cheaply. Arc chains through crowds. Rail pierces everything in a long straight lane. Cryo slows without dealing damage.

Each placement is therefore three decisions at once: what the tower shoots, where it shoots from, and what the wall it creates does to the route.

Building a good maze

The aim is length, not thickness. A long winding corridor exposes packets to your towers for many seconds; a thick block of towers next to a short path exposes them for one.

Build switchbacks. A snaking route that doubles back on itself repeatedly keeps packets inside the same cluster of towers several times over, so each tower earns its cost many times.

Leave your corridors one tile wide. Wider corridors let packets cut corners, which shortens the effective path.

Where to put which tower

Rail wants a long straight, so aim a corridor down its lane rather than placing it and hoping.

Arc wants the place where packets bunch up — usually a corner of a switchback, where the queue folds back on itself.

Cryo is a force multiplier rather than a weapon. It is worth most at the entrance to a long stretch covered by other towers, because slowing a packet before it enters that stretch multiplies the damage everything else does. Placing Cryo at the very end, next to your core, is nearly worthless.

Reading the rewrite

Whenever you place a tower, look at where the route moved to. Sometimes a single wall causes packets to take a completely different corridor, which can leave half your towers shooting at nothing.

That is the most common mistake in this game: a strong maze quietly ruined by one late placement that opened a shortcut.

Economy

Every tower is money that could have been a different tower somewhere better. Early on, prefer cheap towers that build the maze; upgrade once the route is long and you know packets will be walking past them for a while.