Hard, or just unfair? How a shooter earns its difficulty

Everybody has given up on a shoot-'em-up muttering that it cheated. Usually they were right, and usually it was one of four specific things — none of which has anything to do with how hard the game is, and all of which are fixable without making it easier.

One: the hitbox you cannot see

Your aircraft is drawn as a whole aeroplane. The part of it that bullets actually touch is usually a dot near the cockpit, a tenth of the size. That is not a cheat — it is the single best idea in the genre, because it lets a screen full of fire still have gaps you can thread.

The cheat is hiding it. If the drawn aircraft is ten times the size of the thing being tested, and you are never shown which, then every near-miss and every unexplained death is the game scoring you against rules it will not show you. The fix costs one dot: draw the hitbox. Games that do this feel precise. Games that do not feel arbitrary, and it is the same game underneath.

Two: things that arrive where you could not look

An enemy fading in beside you, or entering from the bottom of the screen behind your aircraft, is not difficulty. It is a death you had no information about. The rule that fixes it is simple enough to state in one line: everything enters from the far edge, above the top of the field, and nothing is ever created inside the area you are flying in.

Three: the shot you could not have dodged

This is the big one, and it is the one most cabinets got wrong. If an enemy drifts on top of you and then fires, the bullet arrives before any human could move. The game is not testing your reactions — there is no reaction fast enough — it is testing whether you had already guessed.

The fix is a rule about distance rather than speed: a bullet is never created closer to you than it can travel in some fixed reaction time, say a quarter of a second. An enemy that is too close simply does not shoot. That sounds like it would make things easy, and it does not: the enemy is still there, still in your way, still about to be somewhere else. What it removes is only the deaths you could not have avoided.

It is worth noting that this is a property you can test rather than a feeling you can argue about. Play the game for a few minutes, look at every bullet at the moment it is created, measure its distance to the player, and check none of them is inside the line. If one is, the game is unfair, and you know precisely how much.

Four: the death spiral

The classic design takes every power-up when you die. The logic is that it stops a strong player coasting; the effect is that the life after a bad moment is harder than the one that killed you, and the one after that is harder still. Most players do not fail a shooter — they fall off a cliff and then play three unwinnable lives before quitting.

Dropping a single level of gun is a real cost and leaves you a game. Pair it with a moment of invulnerability on respawn and a cleared screen, so you do not come back into the same bullet, and the genre's worst habit is gone.

What difficulty should actually be made of

With those four removed, what is left is the real thing: how many aircraft, how fast, how densely they fire, how much of the screen is covered at once, and whether you can read it quickly enough. That is a test of attention and planning, and it can be made as hard as you like without ever being unfair.

There is also one rule for the player, which is worth more than all the rest: fly low and move small. Sitting near the bottom of the field gives you the whole screen to read. And because your hitbox is a dot, most of what looks like a wall of fire has gaps far wider than you are — the way through is almost always a nudge, not a dash.

Playing it here

Bomber Run is an original top-down shooter built with all four rules in place, and the page says what each of them is. Free, no account, runs in your browser — on a phone you drag to fly, which is the better way. Three modes: Gentle does not even charge you the barrel.

Related: Invader Drop, which is the opposite shape — pinned to one row with a single shot in the air — and Asteroid Drift, Brick Rebound and Maze Chase.