How Meltdown works

Game manual · Updated 22 October 2026

What is Meltdown?

Meltdown is a fast single-player arena shooter set in a reactor that is going critical. You stand in a round hall with the glowing core in the middle, and machines pour in through portals – wave after wave, each a little tougher and faster than the last. Every fifth wave is a boss wave against the Overseer. A run lasts as long as you survive; your score and the wave you reach are what count.

Meltdown rewards speed and variety. Keep moving, switch weapons and punch projectiles back, and you climb the style rank and earn more points per kill. The game runs in your browser with mouse and keyboard, gamepad or touch, with no sign-up and no download.

First-person view in Meltdown, wave 4: a crawler runs at the player across the reactor hall, behind it the glowing core and pillars
The HUD at a glance: wave and enemies left at the top left, score and style multiplier at the top, style rank on the right, health and the three dash charges at the bottom left – and once the core bar at the bottom is full, E sets off the meltdown.

Controls

  • WASD – move, mouse – look around, left click – shoot
  • Right click – secondary function (detonate a rocket mid-air, railgun zoom)
  • Space – jump, once more in mid-air
  • Shift – dash
  • C – slide on the ground, slam in the air
  • F or V – punch
  • E – trigger the meltdown
  • 1–4, mouse wheel – choose a weapon, Q – back to the last weapon
  • M – switch music, Esc – pause with settings for sensitivity, field of view and graphics

Movement

In Meltdown, movement is your best defence. The dash is a short, very fast burst; you have three charges, each of which refills after a little over a second. During a dash you are briefly invulnerable – even to lasers. Press C on the ground to slide low and keep your speed; jump straight out of a slide and it springs you far forward. In the air, C becomes a slam: you crash down and knock away enemies around you – the higher you fall, the harder it hits. On top of that, jump pads on the floor launch you onto the platforms at the edge.

The weapons

  • 1 – Splinter: a shotgun with twelve pellets per shot. Devastating up close, weak at range.
  • 2 – Ember Beam: a fast plasma rifle. It heats up as you fire and locks at 100 percent until it has cooled down.
  • 3 – Hammer: a rocket launcher with three charges that reload by themselves. Right click detonates the rocket mid-air. Your own explosion throws you – that is the rocket jump, but it costs a little health.
  • 4 – Lance: a railgun that pierces everything in its line. Right click zooms in. It needs a little over a second to charge between shots.
  • Punch: knocks enemies away and – far more importantly – sends enemy projectiles back. A successful parry returns the projectile with four times the damage and heals you.
  • Meltdown: every hit and kill fills your core. When it's full, press E to unleash a massive shockwave.

Headshots do double damage.

Meltdown with the Ember Beam selected: the weapon glows white-hot and the game reports that it has overheated
Hold the Ember Beam down too long and it locks at 100 percent heat until it has cooled off – the heat display at the bottom right shows how close you are, so fire in short bursts.

The enemies

  • Crawler: nimble spider machines that bite and jump onto platforms. Low health, but often in groups.
  • Drone: circles above you and fires slow plasma balls – perfect food for the punch.
  • Soldier: keeps its distance and announces its volleys with a glaring visor.
  • Sniper: a marksman that doesn't move. Its laser tracks you for 1.6 seconds, then it hits. Get behind cover or dash at the right moment.
  • Colossus: a tank on legs with over 500 health. It sends shockwaves along the floor (jump over them!), charges at you and leaps.
  • Overseer: the boss, every fifth wave. It fires fans of projectiles, sweeps the hall with a laser, sends homing mines after you and calls in reinforcements. The mines can be shot down.

Defeated enemies drop green health orbs that fly towards you once you're close enough.

The Overseer boss in Meltdown fires a wide fan of glowing red projectiles, its health bar runs across the top of the screen
Every fifth wave the Overseer arrives with its own health bar at the top of the screen – dash through its fans of projectiles or punch single shots back, which works with every enemy projectile.

Style rank

Every kill earns style, and style raises your rank: D (Dismal), C (Cool), B (Brutal), A (Atomic), S (Supernova), SS (Melting point) and SSS (Meltdown). The higher the rank, the more points per kill – five times as many at SSS. If you always kill with the same weapon, you earn less style. Parries, headshots and streaks give extra.

Upgrades between waves

After every wave you clear, you pick one upgrade from three random cards (with the mouse or keys 1 to 3). Each can be taken one to four times. A few examples: Armor plating (+25 max health), Afterburner (+1 dash charge), Jump springs (+1 air jump), Chain plasma (plasma hits jump to the next enemy), Demolition expert (bigger explosions and no more self-damage), Targeting computer (headshots do 2.6× damage) and Reactor coupling (the meltdown charges faster). So every run plays a little differently.

Upgrade choice in Meltdown after wave 1: three cards – Reactor Coupling, Targeting Computer and Drum Magazine
The small label above each name shows what the upgrade improves, and the diamonds show how many times it can be taken – a filled diamond marks a level you already have.

Strategy and tips

  • Never stand still. Almost every enemy aims where you are right now. Circle, jump, slide.
  • Switch weapons. Splinter for nearby crawlers, Lance for snipers at range, Hammer for groups. Variety also keeps your style rank up.
  • Practise the punch. Returning drone shots is safer than dodging and heals you on top.
  • Snipers first. A sniper you ignore will hit you, guaranteed. Watch for the laser.
  • Jump over the Colossus's stomp. The shockwave travels along the floor; in the air you're safe.
  • Collect health. Grab the green orbs before the next wave arrives.
  • Save the meltdown. Trigger it when several enemies surround you – not against a single crawler.

Common beginner mistakes

  • Holding down the Ember Beam and ending up with an overheated weapon.
  • Firing rockets at close range – your own explosion hits you too.
  • Burning dash charges just to get around and having none left when a laser comes.

Frequently asked questions

Is there a multiplayer mode?

No, Meltdown is a single-player game. You play against your own record.

What is saved?

Your high score, your best wave, and your settings and sound settings stay in your browser's local storage.

Does Meltdown run on a phone?

Yes, with touch controls. For this pace, though, a computer with a mouse or a gamepad is more comfortable.

Behind the scenes

Meltdown uses the 3D library three.js but no physics library. Collision is deliberately simple: axis-aligned boxes, upright cylinders, the floor and the round outer wall – that is all an arena shooter needs. Fast movements such as the dash are split into small sub-steps so nobody slips through thin walls. The weapon in your hand lives in its own little scene and is drawn last, on top of everything, which is why it never disappears into a wall. For impact, the world freezes for a split second on heavy hits, and in special moments time briefly runs in slow motion.

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