Sky Fighter

The sky, and how a level ends

The board is 360×640 units. Your fighter flies left and right at a fixed height near the bottom, and enemies enter from the top a wave at a time. Which enemies enter comes from a fixed seed together with the level and wave number, so every player meets the same formations on the same level, and a golden test keeps them that way.

• Cleared: every wave of the level is empty, whether you shot the enemies down or they flew past.
• Failed: you lose all 3 lives.
• Between waves there is a quiet beat of 0.9 seconds, and your guns stop during it. It is a breath, not a countdown.

Controls

• Drag to fly. Your fighter follows your finger, and the left and right arrow keys work too.
• Firing is automatic and always on. There is no fire button anywhere in the game.
• That is why moving is aiming: the only decision the controls ask of you is where to be.

One axis of control and no fire button is what makes this playable with a thumb on a bus. It also means nothing on screen has to explain itself in fourteen languages.

Three sizes, and what a hit does

There are three kinds of enemy and you tell them apart by silhouette. All of them fly nose down.

• Bomber — the largest. Shoot it and it splits into 2 fighters.
• Fighter — the middle size. Shoot it and it splits into 2 scouts.
• Scout — the smallest. Shoot it and it is gone. The smaller the craft, the more it scores.
• Enemies bounce off the side walls as they come down.
• An enemy that gets past you costs you nothing but its points. It simply flies away; it does not take a life.
• Touching one does: a life goes, a barrel goes with it, and you get 1.2 seconds of invulnerability, shown as a blink.

A bomber becomes seven aircraft before it is finally gone — one, then two, then four — which is why a wave with more bombers in it fills the screen rather than just moving faster.

Only bombers shoot back

• Bombers are the only armed enemy. The fighters and scouts they split into carry no guns at all, so the more bombers you bring down, the quieter the sky gets. Kill the big ones first — the three sizes are a tactical choice, not just a scoring ladder.
• Their shots are slow: 175 against your own 540. They are meant to be stepped around rather than reacted to.
• A bomber fires about every 2.3 seconds, and the interval is staggered per aircraft so a formation never fires as one.
• A bomber still above the top edge of the screen does not fire.
• Being shot is treated exactly like being touched: a life, a barrel, and the same 1.2 seconds of grace.
• Enemy shots are drawn as long tracers, so they never look like your own round ones.

Barrels, the one way you get stronger

There is exactly one power axis in this game: how many barrels you are firing. It goes 1, then 2 parallel, then 3 in a fan. Damage and rate of fire never change, so what is on the screen is the whole rule.

• Only a downed scout can drop a token, and whether it does is decided by the seed and that enemy — the same run always drops in the same places.
• The token is a miniature of your own fighter. Catch it with the ship and you gain a barrel. Only one token is ever on screen at a time.
• A hit costs you one step, not everything. You fall from 3 to 2, not from 3 to 1.
• Every level starts you at one barrel. Power never carries over, so the arc from "weak" to "armed" to "just barely" is rebuilt once per level instead of once per install.
• Barrels are free, earned in play, capped, and gone when the run ends. There is no currency, no upgrade tree, and no barrel is ever sold.

The 100 levels, the score and the help you get

Clearing a level unlocks the next, and any level you have cleared can be flown again. A level holds 4 to 6 waves, later waves are faster and busier than earlier ones, and the last wave of a level is always its hardest.

• Every lever moves continuously with the level number and nothing saturates before 100.
• Best score is one number for the whole game, not one per level. A score is what a run earned, so the points from a run you lost still stand — you shot what you shot.
• There is no Undo and no Hint: the sky moves in real time and nothing is hidden for a hint to reveal.
• The help is an instant, free retry of the same level, the grace period after a hit, and the fact that an enemy flying past costs you no life.
• There is no continue to watch an ad for and no extra life to buy. There is also no mid-run save — leaving the game screen discards the attempt, while your statistics and unlocked levels are always kept.

Statistics are attempts, clears, best score and total play time. No streaks, and no online ranking — a leaderboard is a server someone has to keep paying for.

Questions people ask