Pixel Invaders is a scrolling shooter: you fly up through a sector, waves come at you in patterns, and a flagship is waiting at the end. Three things about it are not obvious and all three decide how well you do.
Objective
Fly up through the sector, stay alive, and bring down the flagship at the end of it. Then do it again, deeper. It does not stop; the run ends when your last ship is gone.
There is no fire button
The ship fires by itself, about seven shots a second, for as long as you are alive. This is deliberate and it is not a simplification.
A shooter played with a thumb cannot ask for a fire button, and holding a key down to fire is busywork rather than a decision. Taking the button away leaves exactly one thing to think about, which is the thing the game is actually about: where to be.
Your hitbox is far smaller than your ship
The ship is nine units across. The part of it that can be shot is four — a small disc at the centre. Wings, fins and engine glow are all decoration.
Every shooter worth playing does this, and most of them never say so. A sprite-sized hitbox makes a dense pattern feel like a cheat, because shots that visibly missed still kill you. A small one means a near miss reads as a near miss, and it is what makes threading a gap possible at all. If a shot looks like it clipped your wing, it did not hit you.
Practically: aim the middle of the ship at the gap, not the whole sprite. There is far more room than there appears to be.
The five things that come at you
| Enemy | Worth | Hits | What it does |
|---|---|---|---|
| Drone | 30 | 1 | Straight down. Never shoots. Cannon fodder, and in numbers |
| Weaver | 50 | 1 | Sine-waves down the screen, takes the occasional aimed shot |
| Darter | 80 | 2 | Comes in fast, slows, curves away. Shoots on the way |
| Turret | 120 | 4 | Stops at a holding line and fires three-way spreads. May drop a power-up |
| Hulk | 250 | 8 | Slow and heavy, throws rings of six you have to move through. May drop a power-up |
Enemies gain a hit point every three sectors, so a drone deep in the run is not the pushover it was in sector one.
Hull, and why a clip is not fatal
Your ship has hull: four points on Pilot, five on Cadet, three on Ace. A hit takes one. Only when the hull runs out do you lose a ship, and the next one arrives with a full hull.
The first version of this game spent a whole ship on every clip, which made the early sectors an exercise in never being touched at all. A small mistake should cost something without ending anything.
The bar of green pips beside the ship count is what is left. A scratch gives you a short moment of invulnerability to get out of whatever caused it; losing a ship gives you longer, and clears the screen.
Asteroids
From sector two, rocks drift down alongside the waves. They never shoot. What they do is stop your fire and break your hull if you fly into one, so a rock sitting between you and a turret is a problem you solve by moving rather than by shooting.
A big one takes six hits and splits into two smaller ones, which means clearing a path takes a moment and a panicked shot can make the problem worse before it gets better. They thicken as you go deeper.
Power
Turrets and hulks sometimes drop a power-up. Collecting one widens your fire: one stream, then two, then three with the outer pair angled.
Losing a ship costs you one power level, not all of them. Dropping straight back to a single stream would turn one mistake into a run that cannot be recovered, which is a punishment, not a difficulty.
Reading a flagship
Every sector ends with one. It takes a great deal of killing — around eighty hits in the first sector, and forty per cent more each sector after — and it changes attack twice on the way down.
| Phase | When | What it does |
|---|---|---|
| One | above two thirds health | Drifts slowly, fires a three-shot spread aimed at you |
| Two | two thirds to one third | Moves faster, fires rings of ten in every direction |
| Three | below one third | Fastest, five-shot aimed spreads, often a ring too, and it starts calling drones down to help |
Throughout all three, it also rakes: it stops dead, announces itself, and drops three columns of fire straight down its own centre line. Directly underneath is the one place the rake is guaranteed to reach.
The bar under the top row is sector progress until the flagship arrives, then it turns red and becomes the flagship's health.
The eyes glow yellow for about half a second before every burst. That is the whole fight. A pattern you cannot read is a lottery rather than a challenge, so the wind-up is there on purpose — move on the glow, not on the bullets.
It has around 170 hit points in the first sector and gains a little under forty per cent per sector after that. With a single stream that is roughly half a minute of held fire; with three it is nearer ten seconds. You will not get either, because of the rake.
Postings
| Posting | Ships | Hull each | Incoming fire |
|---|---|---|---|
| Cadet | 4 | 5 | Much slower to shoot, slower bullets |
| Pilot | 3 | 4 | Standard |
| Ace | 2 | 3 | Faster to shoot, faster bullets |
Sector one is deliberately quiet whichever posting you pick: only two of its eight waves can shoot back at all, and everything fires at well under half its normal rate. Darters arrive in sector two, turrets in three, hulks in four, and the rate climbs steadily until sector five or so.
Controls
| Action | Keyboard | Mouse | Touch |
|---|---|---|---|
| Fly | ← ↑ → ↓ or WASD | move the pointer | drag anywhere |
| Fire | automatic | ||
| Pause | Esc P | the pause button | the pause button |
| Restart run | R | — | — |
On a phone the ship rides a little above your finger rather than under it. A thumb covering the ship is the single worst thing about playing a shooter on a phone, and this is the standard fix.
Strategy
- Stay low and small. The lower you are, the more time you have to see an aimed shot coming and step out of its line.
- Aimed shots are fired at where you are, not where you will be. A small, steady sideways drift beats a panicked jump every time.
- Kill turrets first. They stop and set up, and a pair of them firing spreads from a holding line is what fills the screen.
- Rings from a hulk have gaps by definition. Pick one and move through it early, rather than backing away until it closes.
- Do not sit directly under a flagship. That is what the rake is for, and it will find you there. Fight from its flank: it is fifty-four units wide, your shots still land, and the rake covers only the middle thirty.
- Move on the wind-up. Once the eyes glow you have about half a second, which is plenty if you were not already committed.
Questions
Why is there no fire button?
Because holding one down is not a decision. The ship fires constantly, so the only thing you ever choose is where to be — and it means the game plays properly with one thumb.
That shot definitely hit me. Did it?
Probably not. Only a small disc at the centre of the ship can be hit, about four units across against a nine-unit sprite. Wings do not count.
How long is a flagship fight?
About 170 hits in sector one, rising per sector. Half a minute of held fire with one stream, ten seconds or so with three — but the rake means you will not hold position for either.
I keep losing ships in the first sector. Is it meant to be that hard?
No, and it used to be. Sector one now has only two waves that shoot at all, everything fires at under half rate, and a hit costs hull rather than a whole ship. If it still feels relentless, Cadet gives you five hull and four ships.
Does it ever end?
No. Sectors keep coming, faster and denser, with a tougher flagship each time. The run ends when your last ship does.
Other guides
- Wingbeat — why you should aim low in the gap
- Block Drop — SRS rotation, wall kicks and T-spin scoring
- Fruit Link — the two-turn path rule and board motion
- All guides