Turbo Pudding

TirraleeDev diary

How a chain of bubbles becomes a tune

· The Turbo Pudding team · 4 min read

In a meadow room of Tirralee, Tirra, a round apricot fledgling with a three-feather crest, stands on a grassy ledge with her beak open, having just blown a bubble; inside the bubble floats a green Chirpet, a grasshopper with long feelers, and next to it a Stompling, a brown root with a green sprout and a gray scribble cloud over its head, watches; below, another Chirpet waits on a ledge at the left and Lee, a lilac fledgling with a curl on top and a long curled tail feather, stands on a ledge at the right under a pale sky over green hills

The tagline of Tirralee is “Every bubble is a song”, and we meant it literally. When a caught spirit pops, the game rings a little bell, and when several pop in a row, the bells climb. A good chain doesn’t just score well. It sounds like a tune. It’s Wednesday, so here’s a page from our dev diary about how that works.

The picture at the top is a meadow room. Tirra has just blown a bubble around a Chirpet, and the Stompling beside it is next in line.

No sound files at all

Tirralee doesn’t play recordings. Every sound, from a jump’s light “hup” to the boss’s grumbling roar, is built by the game itself, note by note, the moment it’s needed. That keeps the game small, lets it run offline, and means every note in it is ours. It also means a sound can change with what’s happening on screen, and the bubbles are where that matters most.

A ladder of eleven notes

Popping bubbles climb a ladder of eleven notes, from F to F two octaves higher, using only five notes per octave: F, G, A, C and D. Musicians call this a pentatonic scale. It has no notes that clash, so whatever order the bells ring in, they sound good together. And it’s in F, the same key as the game’s songs, so the bells always sit nicely on top of the music.

The first critter in a chain rings the bottom F. Each next one jumps two rungs higher: A, then D, then G, then C, then the top F. From the second pop on, a quieter bell rings two rungs above the main one, like a tiny echo. Pop six spirits in one go and you hear a whole rising phrase.

How a chain spreads

A chain starts when you pop one bubble. Any bubble touching it starts to pop too, five steps later. The game runs sixty steps a second, so that’s about a twelfth of a second per link. It’s quick enough to feel like one big burst, and slow enough to hear every bell in turn. That little delay is the whole trick: without it, six bells would ring at once and you would hear one blurry chord instead of a tune.

Empty bubbles join the chain with a tiny “pip” and no bell, so the tune belongs to the spirits you’ve set free.

Tirra, the apricot fledgling, stands at the bottom left of a rainy room in front of a staircase of gray stone columns, each one higher than the last; a different treat sits on top of each step, rising from a red apple at her feet to a bun, a rice ball, a slice of cake with a cherry, a ring-shaped cookie, a cup of green tea and a pink ball at the very top, under a soft blue sky with clouds
Search: “platformer with food”. Every step up the chain tastes better.

Bigger chains, bigger gifts

The tune isn’t the only thing that climbs. Each spirit you set free in a chain is worth twice as much as the one before: 100 points, then 200, then 400, all the way to 6,400 for the seventh. The treat it drops climbs too, through seven treats from 50 points to 5,000, and the treat’s sparkle rings a step higher on the same ladder. Pop four at once and the room gives you a present, once per room.

When dusk falls

Stay in a room long enough, usually about half a minute, and the sky darkens. “DUSK!” appears, a music-box alarm ticks four times, and the room’s song speeds up by about a quarter. Ten seconds later the Duskmoth arrives with a low, breathy “hooo”.

The way out is the same bubbles. A chain of three, or a freed firefly, brings the light back. “Light!” appears, a warm rising chord rings out, the song slows back down, the Duskmoth flies off, and the room’s clock steps back so dusk is a little further away again.

At dusk in a rainy room of Tirralee, the colors have turned gray and violet; two angry Stomplings with dark storm clouds over their heads stand on a long stone ledge at the top, the big purple Duskmoth with spotted wings hovers at the left, and below, Tirra, the apricot fledgling, stands on a small ledge in a soft circle of light, looking at a firefly glowing inside a bubble in front of her
Searched “cozy game”. Then dusk fell. Pop three, get the light back.

Little rules so it never grates

A sound you hear a hundred times an hour has to stay pleasant. So each common sound comes out slightly higher or lower every time, just a few percent, and the game never plays too many copies of the same sound at once. Tirra and Lee also blow and jump on slightly different pitches, so in a two-player game you can hear who did what without looking.

On a starry night in Tirralee, a golden bubble with a musical note inside glows between two ledges, surrounded by short rays of light; Tirra, the apricot fledgling, stands on the ledge below it at the left, Lee, the lilac fledgling, stands on the ledge at the right, and a sleepy white cloud spirit with a gray scribble cloud over its head dozes on a ledge in the upper left corner
Typed “music platformer”. Got a golden note that hums the theme.

The song you’re collecting

Every room hides a golden note. When you take one, the bells play the first five notes of the waltz from the title screen, so every note you find hums a piece of the game’s own song. Find all fifty to see the true ending. We won’t say more than that.

The first two levels of Tirralee are free, alone or with a friend on the same keyboard. Turn the sound on, catch three spirits and pop them together, and listen to the bells climb.

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