Swarm Zero: Free Horde Survival Game Online

What is Swarm Zero?

Swarm Zero is a horde survival game where the only thing you do is move. Glim, a small lantern-bot, guards a ring of light, and the Null come out of the dark for it: a few dozen at first, then hundreds, then thousands.

Every weapon aims and fires by itself. Your whole job is where to stand, which way to run and what to pick. Each Null you destroy drops a shard, shards fill your level bar, and every level offers three upgrades. Take one and the swarm melts a little faster.

The light grows each minute, so the arena keeps getting wider and the swarm keeps getting thicker. A great Null arrives every three minutes. At 15:00 comes Zero Hour: the light closes in and ZERO itself turns up. Beat it and the run carries on for as long as you can hold.

It is free in your browser on a phone, tablet or computer, with no download and no account. There are four ways to play: Calm, Standard, Onslaught and a Daily run where everyone gets the same swarm.

How to play Swarm Zero

1. 

   1Pick a mode and press Play

   Choose Calm, Standard, Onslaught or Daily along the top of the menu, then press Play. Calm is a kind first run. There is nothing else to set up.

2. 

   2Steer Glim, and only steer

   Move with WASD, the arrow keys, a held mouse button or a thumb on the screen. Glim's weapons pick their own targets and fire by themselves, so keep moving and let them work.

3. 

   3Collect shards to level up

   Every Null you destroy leaves a shard. Run over them, or just pass close and they fly to you. The bar across the top shows how near the next level is.

4. 

   4Choose one of three upgrades

   A level up stops the action and deals three cards. Take a new weapon, raise one you own, or add a passive. Click or tap a card, or press 1, 2 or 3. Reroll if none of them suits your build.

5. 

   5Feed the combo

   The badge beside your score is your combo. Every kill feeds the streak, and the streak lifts your score multiplier step by step to ×10. Go three seconds without a kill and it is gone, so stay where the Null are thickest.

6. 

   6Rescue the Glimmers

   A small lantern with a shrinking ring is a stranded Glimmer. Touch it before the ring closes. It joins you, shoots for the rest of the run and pays a bonus that grows with every rescue in a row.

7. 

   7Hold out to Zero Hour

   A great Null arrives every three minutes. At 15:00 the light closes in and ZERO appears. Hit it while its petals are open, keep clear of its pull, and bring it down to win. Then play on for score.

The rules in full

1. Choose Calm, Standard, Onslaught or Daily on the menu and press Play. The run starts straight away.
2. Move with WASD or the arrow keys. With a mouse, hold the left button and Glim heads for the pointer. On a touch screen, put a thumb down anywhere and drag: a stick appears under it. A gamepad works too.
3. You never press fire. Your weapons aim and shoot on their own, so steer Glim to where the shots do the most good and the Null do the least harm.
4. Run over the shards the Null drop. When the bar along the top fills you level up and three cards appear. Click or tap one, or press 1, 2 or 3.
5. Do not like the three cards? Press R or the Reroll button for a new set. You get three rerolls a run.
6. You can carry five weapons and five passives. Weapons grow to level 6 and passives to level 5.
7. Get a weapon to level 6 while you hold its partner passive and an evolution card turns up. Evolutions are the strongest things in the game.
8. Keep the kills coming to build your combo. It multiplies every point you score, up to ×10. Three seconds without a kill and it drops back to ×1.
9. Reach a stranded Glimmer before its ring runs out to rescue it. Rescued Glimmers follow you and fire, and each rescue pays a bonus and mends a little hull.
10. The run ends when your hull reaches zero. Press P or Esc to pause and M to mute. If you close the page mid-run, you can resume from the menu.

Swarm Zero tips and strategy

• Move in wide circles. The swarm bunches up behind you, and bunched Null are what Orbit, Nova and Arc do their best work on.
• Pick two or three weapons early and push them to level 6. A few strong weapons beat five weak ones every time.
• Know the partner before you choose the passive. Pulse wants Overclock, Orbit wants Reach, Arc wants Amplifier. Every card names its partner, so you never have to guess.
• Elites wear a gold crown and always drop a cache. A cache evolves a weapon that is ready, so hunt the crown when you are one step away.
• A Blight does not hurt on touch. It stops, swells and bursts. Walk it into a crowd and step back: the blast tears through other Null as well.
• Darts pause for a moment, then streak in a straight line. Step sideways as they wind up and the whole pack sails past.
• Taking a hit knocks your combo down three steps. Late in a run that costs far more than the hull does, so dodge first and score second.
• The last ten seconds of every minute are a surge. Use the quiet start of the next minute to sweep up shards and reach a Glimmer.

What kind of game is Swarm Zero?

It is an arena survival game with one stick and no fire button. You steer, your weapons shoot, and the screen fills with more enemies than you would think a browser could draw.

A run is a build. You start with one weapon and end with five, plus five passives and a handful of evolutions. No two runs hand you the same cards, so no two builds come out quite the same.

The eight weapons

Pulse fires bolts at the nearest Null. Orbit spins blades of light around you. Arc throws lightning that jumps from one Null to the next. Nova bursts outward and shoves the swarm back.

Lance fires a piercing beam the way you are heading. Seekers send out homing sparks. Mines drop charges behind you. Sentry plants a turret that covers the ground you leave.

Passives and evolutions

The eight passives are Amplifier, Overclock, Reach, Thrusters, Magnet, Plating, Regenerator and Battery. They add damage, fire rate, size, speed, pickup range, hull, healing and duration.

Each one is also the key to an evolution. Pulse with Overclock becomes Storm Pulse. Orbit with Reach becomes Corona. Arc with Amplifier becomes Thunderhead. Nova with Plating becomes Supernova.

Lance with Battery becomes Sunbeam. Seekers with Magnet become Hive. Mines with Thrusters become Comet Trail. Sentry with Regenerator becomes Watchtower.

Get the weapon to level 6, own the passive at any level, and the evolution appears as a gold card on a later level up, or drops out of a cache.

Know the Null

Mites are the bulk of every swarm: weak, and endless. Husks are slow and soak up fire. Darts wind up and streak across the arena in packs. Weavers spiral in instead of running straight at you.

Spitters hang back and lob slow orbs, so go and get them. A Brood splits into Mites when it dies. A Blight rushes in, swells and bursts. Shades cross the light in sudden dashes.

Any of them can turn up as an elite with a gold crown: bigger, tougher, and carrying a cache. Now and then the Null try something together, such as a closing ring or a stream of Darts from one side.

The great Null and Zero Hour

The Maw comes at 3:00 and charges in straight lines. The Matron comes at 6:00, hatching Broods and firing rings of shots. The Loom comes at 9:00, circling you while it fires spirals.

The Eclipse Twins come at 12:00 and sweep a tether between them. You do not have to kill a great Null to carry on, but each one is worth a pile of points and drops a cache and a repair.

At 15:00 the light shrinks and ZERO arrives. It shrugs off most damage while its petals are shut, and it drags you towards it. Beat it and you have won the run. After that the great Null return, stronger, about every two minutes.

How scoring and the combo work

Every kill scores, and the combo multiplies it. The steps are 10 kills for ×2, then 25, 50, 100, 200, 400, 800 and 1,500, with ×10 at a streak of 3,000.

The streak ends if three seconds pass without a kill. The Battery passive slows that clock. A hit does not end the streak, but it knocks the multiplier down three steps.

Rescues pay 1,000 points for the first Glimmer and more for each one after it, up to 5,000, as long as you never lose one. All of it is multiplied by your combo, so a late rescue at ×10 is huge.

Calm, Standard, Onslaught and Daily

Calm thins and slows the swarm and gives you a tougher hull. Scores count for 60%. It is the place to learn the weapons.

Standard is the game as it was meant to be. Onslaught sends more Null that hit harder and move faster, and scores count for 150%.

The Daily run uses one seed for everyone that day, on Standard rules: the same swarm and the same upgrade offers. It is the fairest way to compare a score with a friend.

Thousands of enemies, running smoothly

Swarm Zero was built to hold a real horde. The engine has been measured with 5,000 Null alive at once at a steady 60 frames a second on a desktop computer.

It draws the whole swarm in one pass on your graphics chip, and falls back to a simpler renderer on devices that cannot. The Settings panel shows which one you are using.

Screen shake, damage numbers and music can each be switched off. If your device asks for reduced motion, shake and flashes stay off by themselves.

Swarm Zero FAQ