Swarmline

They come in thousands. Hold the line.

Play Swarmline — free, in your browser

A living swarm pours down an endless road and you are the only thing standing in it. Your line of troopers runs and fires automatically — all you control is where it stands, how tightly it holds, and when it breaks. Hold FOCUS and the line condenses into a lance: piercing fire that punches through armour and melts a corridor straight up the road, at the cost of a narrow escape window. Let go and it fans into a sweeping net that mows loose swarm off the flanks. Gates still do math on your numbers — green adds, gold multiplies, red subtracts, and a red gate can be shot green before you reach it — but the road between them is now a flood. Bloaters detonate when they die, and one well-placed shot in a dense pack can rip a hole through hundreds. Armoured husks shrug off spread fire, spitters lob mortars at wherever you are standing, and brood callers knot the swarm around themselves. Every few hundred metres a Hivemother walks the road, venting fresh curtains of brood until you break its nodes and burn its core. Charge the SURGE meter and you can send a wave of your own straight up the lane. How far can you hold?

Controls

How to Play Swarmline

Your line runs and shoots on its own. What you control is position and shape — steer with a drag or the arrow keys, and hold FOCUS to change how the line fights.

Spread (the default) is wide, sweeping fire. It is how you clear loose swarm across the road and how you cover several lanes at once, but individual shots stop at the first body they hit.

FOCUS condenses the line into a lance. Shots pierce through several enemies, damage goes up, and your silhouette gets small enough to thread a gap — but you turn slower, so commit early.

Gates do math on your numbers: +N adds troopers, x2 and x3 multiply, −N subtracts. They come in pairs and you can only take one. A red gate is a target, not a wall — pour fire into it and it climbs toward green.

Bloaters are the bright green ones. Killing one detonates it, and the blast kills everything packed around it. Wait until they drift into a crowd and the chain does the work for you.

Armoured husks take almost nothing from spread fire and fold to a focused lance. Spitters hang back and mark the ground before a mortar lands. Brood callers pull the swarm into a knot and vent more of it.

Kills charge the SURGE meter. Releasing it sends a wave up the whole width of the road — it shreds the swarm, shatters blocks, and takes a chunk out of a Hivemother.

Score is banked per kill and multiplied by how fast you are killing right now, plus distance, gates and bosses. The run ends when the last trooper falls.

Four difficulties, chosen on the start card and again on the death screen: SKIRMISH, HOLD, OVERRUN and LAST STAND. They change how much swarm arrives, how hard it is to put down and how big a line you start with — never what you are allowed to do. Every weapon, gate and Hivemother is on every setting, and there is one leaderboard: a harder setting multiplies your score, an easier one scales it down.

Swarmline Strategy Guide

  1. Shape beats position. Most deaths are standing in spread when a husk or a dense column arrives — focus early, punch the hole, then release to sweep what spills around you.
  2. Never shoot a bloater in open road. Let it drift into the thickest part of the swarm first; the same bullet is worth five kills or two hundred depending on when you fire it.
  3. A x2 only beats a +10 when you are already above ten. Do the arithmetic on every pair — multipliers on a thinned line are a trap, and the pair after a bad wave is usually the additive one.
  4. Save SURGE for the moment the road is full, not the moment it is ready. It scales with what is in front of it, and a full-lane release during a deluge is worth several times the same button during a lull.
  5. The combo multiplier tracks your kill rate right now, so it pays to bank a cascade and a surge together rather than spacing them out.
  6. On a Hivemother, break the nodes before touching the core — the core barely takes damage while a node is up, and each node you pop blows a hole in the brood around it.
  7. When you are surrounded, run to a rail. The swarm funnels toward you, so the edge of the road halves the directions it can come from.
  8. Play the setting that keeps you leaning in. LAST STAND pays nearly twice what SKIRMISH does, but a longer run on a setting you can read will out-score a short one on a setting that flattens you.

Questions & Answers

What is Swarmline?

Swarmline is a free browser-based swarm survival game. A living swarm of thousands pours down an endless road and your line of troopers fires automatically while you steer it, change its shape, and pick the gates that grow or shrink it. The run ends when your last trooper falls, and your score goes on the global leaderboard.

Is Swarmline free?

Yes, Swarmline is completely free to play in your browser. No download, no signup, no paywall.

What does FOCUS do?

Holding FOCUS condenses your line into a tight lance. Your shots pierce through several enemies instead of stopping at the first, damage goes up, and your silhouette gets small enough to thread a gap — but you turn more slowly. Releasing it fans the line back into a wide sweeping net that clears loose swarm across the road. Choosing between the two, moment to moment, is the core of the game.

What is the SURGE meter?

Kills charge the SURGE meter at the bottom of the screen, and chains charge it faster. When it is full, one button sends a wave the full width of the road: it shreds the swarm in its path, shatters number blocks and takes a large bite out of a Hivemother. It is worth far more released into a full road than into a quiet one.

How do chain reactions work?

Bloaters are the bright green swarm members, and they detonate when killed. The blast kills whatever is packed around them, which can set off other bloaters in turn. Shooting one in open road is worth a handful of kills; shooting the same one after it has drifted into the middle of a dense wave can take out hundreds at once.

How do the gates work?

Gates arrive in side-by-side pairs and you can only pass through one. Green +N gates add troopers, gold x2 and x3 gates multiply your line, and red −N gates subtract. Red gates can be shot: every bullet that hits one raises its value, so with enough sustained fire a −15 flips into a green bonus before you reach it.

What is the Hivemother?

The Hivemother is the boss that walks the road every few hundred metres. It is not simply a large enemy — it vents fresh curtains of brood while it advances and reshapes the swarm around itself. Its core barely takes damage while its orbiting nodes are alive, so you break the nodes first; each one you destroy blows a hole in the brood nearby, and killing the Hivemother clears the field.

How is the score calculated?

Each kill banks points for that enemy type, multiplied by how fast you are killing at that moment, and distance, gates passed and bosses killed all add on top. It is an endless run — difficulty keeps escalating until your line is wiped, and higher scores rank higher on the leaderboard.

Can I change the difficulty?

Yes — four settings, picked on the start card and again on the death screen, so you can change your mind the moment a run ends. SKIRMISH gives you room to learn the shapes, HOLD is the intended balance, OVERRUN sends more of the swarm sooner, and LAST STAND does not let up. Difficulty only changes what the swarm does to you: every weapon, gate, set piece and Hivemother is available on all four. There is a single leaderboard, and your score is scaled by the setting you played — LAST STAND pays 1.9x, SKIRMISH 0.7x.

Does Swarmline work on mobile?

Yes. Drag anywhere on the screen to steer the line, hold the FOCUS button to condense it, and tap SURGE when the meter is full. Firing is automatic. On desktop you can also steer with the arrow keys or A and D, hold Shift to focus, and press Space to surge.

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