How Repulsor works

Game manual · Updated 2 November 2026

What is Repulsor?

Repulsor is a side-scrolling arcade shooter. You fly an armoured suit over the rooftops of a city at night and hold off ten waves of drones. After the fifth and the tenth wave a boss arrives. A full run takes about four to six minutes, and your best score is saved in your browser. It runs right in your browser – no download, no account.

Repulsor title screen: the game name over a city skyline at night, below it the controls for mouse, left mouse button, space bar and pause, and the current best score
The title screen lists the controls and your best score. Click or press Enter to start.

Controls

  • Fly: move the mouse – the suit follows the pointer with a little inertia. W A S D or the arrow keys work too.
  • Repulsor beam: left mouse button. Hold it for continuous fire.
  • Core beam: hold the space bar once the bar at the bottom right is full.
  • Pause: P or Esc. Sound: M. Start and new run: Enter or a click.

On a phone or tablet, hold it sideways: drag with one finger anywhere to fly – the suit moves with your finger without being covered by it – and it fires as long as your finger is down. Hold the round beam button at the bottom right for the core beam; pause is at the top right.

Enemies

  • Swarm drones fly in groups in wavy lines and try to ram you. One hit destroys them.
  • Gunners stop at the right edge and aim at you – a short flash warns you before they fire. They take four hits and often drop a green energy cell.
  • Kamikaze drones hover, start flashing and then dive straight at you. Two hits stop them.

Each wave brings more and faster drones. Between waves you get a short pause, 10 energy and a wave bonus.

Repulsor in wave four: the red and gold suit fires bright beams at drones, hits show +100, a gunner aims from the right, the bars at the bottom show energy, the wave and the full core beam
Wave four: hits score points, the chain at the bottom raises your multiplier.

The core beam

Every kill charges the core beam bar at the bottom right. Once it is full, hold the space bar: the suit charges for a moment and then fires a wide beam across the whole screen. It destroys every drone on screen and deals heavy damage to bosses. While charging you move slowly and cannot shoot, so pick a quiet moment. On a phone, hold the round beam button instead of the space bar.

Repulsor firing the core beam: a wide white and teal beam stretches from the suit to the right edge of the screen, the core beam bar at the bottom right is empty again
The core beam clears the screen – then the bar starts from zero.

Power-ups

Destroyed drones sometimes drop a capsule – gunners and kamikaze drones more often than swarm drones. Fly into it to collect it:

  • S – Spread shot: two extra beams fan out above and below for 10 seconds.
  • R – Rapid fire: almost twice the rate of fire for 10 seconds.
  • O – Shield: a bubble around the suit that absorbs one hit. You can stack up to three.

Active power-ups and their remaining time are shown above the energy bar. Clear a wave without taking a hit and you get a flawless bonus on top.

Bosses

After waves five and ten a warning appears, followed by a boss with its own health bar at the top: first the Warden Mk I, then the bigger Colossus Mk II. Bosses fire spreads of shots, send out drones and get faster the more damage they take. Bosses drop energy cells, and the core beam is the best way to take a big chunk off their health.

Repulsor boss fight in wave five: the Warden Mk I flashes white after a hit on the right, a fan of orange shots flies towards the suit, the health bar at the top shows about three quarters
The Warden in wave five. Its health bar is at the top of the screen.

Energy, chain and score

  • Energy: every hit costs energy; after a hit you are briefly invulnerable. At 0 % the suit goes down and the run is over. Green energy cells restore 20 %.
  • Chain: kills in quick succession build a chain. Every five kills in a row raise the multiplier by one, up to ×5. A hit, or a pause of about two seconds, resets it.
  • Victory bonus: if you clear all ten waves, leftover energy and a fast time give extra points.
Repulsor end screen: Suit down, waves cleared 4, score 11430, time 1:32, new high score, and a prompt to click or press Enter to play again
When the suit goes down you see your waves, score and time – and whether it is a new best.

Tips

  • Stay on the left. You get more time to react to drones coming in from the right.
  • Gunners first. They are the main source of damage – and of energy cells.
  • Keep moving vertically. Kamikaze drones dive where you were, not where you are going.
  • Save the core beam for crowded moments or for a boss, rather than firing it as soon as it is ready.
  • Protect your chain. A long chain is worth more than a risky kill.

Frequently asked questions

Does Repulsor cost anything?

No. Repulsor is free, without purchases and without an account.

Is my high score saved?

Yes, in your browser on this device. If you clear your browser data or use a private window, it is gone.

Can I play on my phone?

Yes. Turn your phone sideways and play with one finger; the game switches to full screen when you start.

Behind the scenes

Repulsor is drawn entirely in code on a 2D canvas – the suit, the drones and the city skyline are simple shapes, with no image files. The background is rendered once in advance so the game stays smooth on slower computers. Every sound, from the repulsor shots to the boss warning, is synthesised live in your browser.

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