Horizon Panic: low-level flight through a canyon that never repeats

Horizon Panic is a side-scrolling arcade game built with HTML5 Canvas and plain JavaScript. You fly a fighter just above the ground through a procedurally generated canyon, and the real enemy is the scenery: touching the rock destroys the ship instantly. Nothing to install, it runs right in your browser, for free.

How to play

• The ship moves in all four directions inside the left 40% of the screen: you can push forward to slip through a gap before it closes, or brake to let a peak go by.
• The cannon fires straight ahead and only reaches what flies. The bomb falls in an arc and is the only weapon against the ground, so you have to dive to drop it exactly where the terrain is most dangerous.
• A level is a distance covered, not a wave. The terrain never stops between levels: the speed rises, the gap narrows and more enemies arrive, without a single loading screen.
• Every 5 levels a three-phase guardian waits in a clear arena stretch. Beating it grants a permanent upgrade that outlives the ship you are flying.

Controls

Weapons

• CANNON — Straight shot. Only reaches what flies.
• BOMB — Falls in an arc. The only weapon against the ground.

Touching the terrain destroys the ship instantly. Flying low raises an air cushion that softens the fall.

Procedural terrain

The scenery is chained together from stretches, so every run is different: flats, hills, mountains, spikes, canyon, tunnel, narrow pass and the boss arena. Two rules govern it. The ceiling is never generated as an independent curve, but by subtracting a gap from the floor profile with an absolute minimum, so there is always a way through. And two hard stretches are never chained back to back, so there is always a breather.

Enemies

• FIGHTER — Comes head-on in a zigzag and shoots.
• DRONE — Chases your altitude. It rams instead of shooting.
• MINE — Floats where the gap is narrow. The cannon downs it.
• TURRET — Dug into the ground. Only a bomb takes it out.
• TOWER — Unarmed ground target. Scores high.
• DEPOT — Blows up in a chain and drags down whatever is close.

Scoring

Power-ups

• POWER — One more shot: double, then triple.
• LASER — Temporary beam that wipes out anything near it.
• TWIN SHIPS — Escort that echoes your shot. Up to 3; the 3rd orbits.
• SHIELD — One layer per hit, up to 3. Rock breaks it whole.
• RATE OF FIRE — Shoot much faster, for a while.
• SPECIAL BOMB — Stores up to 3 charges. Press N to clear the screen.
• EXTRA LIFE — One more ship, up to a maximum of 5.
• INVULNERABILITY — Immune and faster. Ram them. Rock still kills.
• MAGNET — Pulls nearby power-ups to you for a few seconds.

Bosses and rewards

The guardian is the only enemy with a health bar: the cannon hurts it and the bomb hurts it far more, and the level will not advance until it falls. Each victory grants a permanent reward — tuned cannon, reinforced payload or armour — that stacks for the rest of the run, even if you lose ships along the way.

• TUNED CANNON — Fires faster for the rest of the game.
• REINFORCED PAYLOAD — Bombs come quicker and blast wider.
• ARMOUR — A shield that rebuilds itself after breaking.

Play in your language

Horizon Panic is available in Spanish, English, Portuguese, Galician, Catalan, Italian and French. Pick your language:

You are playing in English.