Space Invaders

Classic arcade shooter, blast the alien fleet as it speeds up wave by wave

FAQ

How do I control the ship?

Use the left and right arrow keys or A and D to move, Space or J to fire, and P to pause. On phones, hold the Left, Fire, and Right buttons under the board to steer continuously.

How is the score counted?

Bottom-row aliens are worth 10 points, middle rows 20, and the top rows 30, so clear the valuable rows first. Clearing a wave starts a faster one with denser fire, and your total keeps adding up.

Do the bunkers break?

Yes. Each bunker is built from small blocks, and shots from both sides chew real holes through them. A gap you fire through works just as well for enemy bombs, so keep an escape route ready.

Is the high score saved?

The best score is stored in your browser's localStorage under the key t55k6-space-invaders and survives refreshes. In private mode the write is skipped silently, which never blocks play.

How to use

Press Start
Hit Start and your ship takes position at the bottom of the field. Move with the arrow keys or A and D, fire with Space or J, and pause with P at any time.
Read the fleet
Fifty-five aliens in five rows slide sideways as one block. Each edge touch drops the fleet a row and reverses direction, so watch its height, not just its position.
Aim your shots
Only one player bullet can be on screen. Bottom rows pay 10 points, middle rows 20, and top rows 30, so clear the valuable rows first when lines overlap.
Use the bunkers
Three block-built bunkers absorb shots from both sides and erode shot by shot. Fight from a fresh bunker and relocate before your cover is gone.
Survive the endgame
The fleet speeds up as it shrinks and again every wave. Strafe to dodge bombs, fire in the gaps, and stretch your three lives as far as they go.

About this tool

Space Invaders in this browser build keeps the arcade loop intact. A fleet of fifty-five aliens marches in five rows and drops lower each time it touches an edge, reversing as it goes. You pilot the lone ship at the bottom, and every shot counts because only one bullet can exist on screen at a time. Rows pay out by depth, with ten points at the bottom, twenty in the middle, and thirty at the top. Each kill nudges the fleet faster, and clearing a wave starts the next one at a higher pace with denser returning fire.

The three bunkers in front of your position are consumables, not safe houses. Every shot from either side chews real holes through the blocks, and a gap you fire through works just as well for enemy bombs. Bomb frequency rises as the fleet shrinks, so the cleanup phase of a wave is often the most dangerous part. Losing a life costs you position and momentum, and three hits end the run. Your best score is stored locally in the browser, so you can close the tab and keep chasing the record on your next visit.

How it works

The original Space Invaders shipped in 1978, designed and programmed by Tomohiro Nishikado. It established patterns shooters still follow: waves of descending enemies, escalating speed, and a single shot on screen that makes accuracy beat raw volume. Hardware limits shaped the design, since the game ran faster as fewer aliens remained, and the developer kept the quirk as a feature. That tension between a shrinking fleet and a rising pace is why the last aliens of a wave feel so much deadlier than the first.

This build separates game logic from rendering and advances the simulation in fixed time steps. The pace therefore feels the same on a phone and on a desktop regardless of frame rate. The field is a fixed 480 by 360 grid scaled to your screen. Touch players get dedicated left, fire, and right buttons. Keyboards work with both arrow and WASD layouts. Scores live in your browser's localStorage and nothing is uploaded. The game pauses itself when the tab loses visibility, so switching away never costs a life.

When to use it

Short breaks
A full run usually lasts two or three minutes, which fits a commute wait or a coffee pause. The page opens straight into the game with no account and no download. The high score stays in your browser between sessions, so every spare minute can go toward beating your own record.
Family leaderboard
The rules fit in one sentence: move, shoot, and do not get hit. Passing a phone or laptop back and forth for the high score turns a nostalgic shooter into a small family tournament. Kids pick up the hand-eye rhythm while parents explain where the game came from.
Arcade feel at home
On a keyboard the game plays closest to the 1978 cabinet: arrows or WASD to steer, Space to fire, P to pause. The shrinking bunkers and the fleet that speeds up as it thins out recreate the coin-era pressure without needing an emulator or a single coin.

Tips & tricks

Clear the top rows first, they pay triple compared to the bottom row.
Fire through gaps you already made in a bunker to keep your exposure short.
Late in a wave, strafe first and shoot second, the last aliens move almost twice as fast.

Things to watch

Watching bullets, not the fleet
The formation drops a row the moment it touches an edge, and that drop is easy to miss while you line up a shot. Glance at the fleet height between shots. A block that was safely above the bunkers can be on top of you within a few seconds.
Holding fire forever
Only one player bullet exists at a time, so holding the fire key just chains misses at the fleet's tempo. Aim before pressing, pick at the edges of the formation, and let the bullet travel instead of firing again the instant the lane is clear.
Trusting worn bunkers
Bunkers erode from both sides, and a late-wave bomb can slip through a hole you made yourself. When your cover looks ragged, move to the thickest one early. Relocating under bomb fire is far harder than moving while the fleet is still high.