Turbo Pudding

TirraleeDev diary

The small numbers behind a friendly jump

· The Turbo Pudding team · 5 min read

In the Rainbow, a meadow room of Tirralee, Tirra, a round apricot fledgling with a three-feather crest, rises with wings flapping past the end of a long grassy ledge near the top of a full jump; below and to the right, Lee, a lilac fledgling with a curl on top and a long curled tail feather, is a little way above a lower ledge in a short hop, over a small white puff of dust; a Stompling, a brown root with a green sprout and a gray scribble cloud over its head, stands on a ledge at the left, two green Chirpets, grasshoppers with long feelers, wait on the ledges to the right, and soft green hills rise under a pale sky

The thing you do most in Tirralee is jump: onto ledges, off ledges, over spirits and onto bubbles, all the way up the Skyward Tree. So before we built a single room, we asked one question: how should a jump feel? It’s Wednesday, so here’s a page from our dev diary about the small numbers behind the answer.

The picture at the top is the Rainbow, in the meadow. Tirra is near the top of a full jump, past the end of the middle ledge. Lee only tapped jump and is in a short hop, just above a puff of dust.

Sixty steps a second

Tirralee counts time in steps. The game moves everything forward exactly 60 times a second, on every computer and every phone, and on a screen that refreshes 120 times a second, it draws the pictures in between. Because the steps never change, a jump is the same height for everyone, and the checker that tests every room uses the very same numbers.

Hold for high, tap for low

A jump starts fast and slows down as it rises. Held all the way, it takes a fledgling about 4.7 tiles up, which is why the ledges in most rooms sit four rows apart. Let go of jump halfway up, and the fledgling loses more than half of its upward speed on the spot. A tap is a hop, a press is a jump, and you decide while you’re already in the air.

A fall you can steer

Coming down is slower than going up. A fall never gets faster than 4.4 pixels a step, less than half the speed of a takeoff, so Tirra and Lee float down with their little wings flapping. You can steer the whole way, too: in the air, a fledgling picks up speed almost as quickly as on the ground.

Stop steering, and on the ground, Tirra and Lee stop within a few steps. In the air, they drift on a little. After a long fall, a fledgling squashes down for a moment and kicks up a puff of dust, and the crest and tail feathers bounce after the body like springs.

A tenth of a second of mercy

Two small tricks forgive almost every near miss. Game makers call the first one coyote time. Run off the end of a ledge, and for six steps, a tenth of a second, the game still lets you jump as if you were standing on it. In the woods picture below, Tirra has just run past the end of a ledge, and there’s still time.

In the Campfire, a woods room of Tirralee, Tirra, a round apricot fledgling with a three-feather crest, has just run off the right end of a long grassy ledge and hangs in the air beside it, beak forward; on the ledge behind, Lee, a lilac fledgling with a curl on top and a long curled tail feather, watches, and a Stompling, a brown root with a green sprout and a gray scribble cloud over its head, stands farther back; a red Spotkin, a ladybird with black spots, flies at the top right by a ledge in front of a white cloud, another Stompling stands on a dark wooden step below, and green pine trees rise at the bottom against a pale yellow sky
Searched “platformer coyote time.” Got a bird instead.

The second trick is a jump buffer. Press jump a moment too soon, just before you land, and the game remembers it for seven steps. The jump happens the instant your feet touch the ledge. With these two tricks, you mostly don’t notice anything at all, and that’s the point.

Bubbles you can stand on

A fresh bubble shoots forward for 17 steps, about five and a half tiles for Tirra and four for Lee, and that’s the only time it can catch a spirit. Then it slows down and drifts. Tirra’s bubbles are small, so the game gives them a little extra reach, and the small size never costs a catch. And your own bubble won’t pop in your face: while it’s still shooting forward, you can touch it safely.

You can also stand on bubbles. Land on top of one while holding jump, and you bounce up almost as high as a full jump, while the bubble dips under your feet with a boing. Without jump held, a touch pops it.

At night in the Lantern, Lee, a lilac fledgling with a curl on top and a long curled tail feather, bounces up off a big clear lilac bubble, feet just above it, toward a long ledge of lavender stone blocks; two Burrnuts, round green chestnut cases with spikes, brown faces and gray scribble clouds over their heads, sit on top of the ledge on both sides of a stone pillar, a smaller apricot bubble floats in the middle, and Tirra, the apricot fledgling with a three-feather crest, watches from a ledge on the right under a dark purple sky with a few tiny stars
Typed “can you bounce on bubbles.” Lee says yes.

Where the bubbles go

Left alone, bubbles rise. In most rooms, they drift up and gather near the middle of the ceiling, right under the gap, and push each other softly apart so they don’t melt into one blob. That’s where a whole bunch can wait for one big chain.

In the Balloon bunch, a pink cloud room of Tirralee, six bubbles, small apricot ones and big lilac ones, crowd together under the gap in the middle of the lavender ceiling; on a white block ledge at the left, Tirra, the apricot fledgling, has just blown a seventh small bubble that flies toward the bunch, and on a matching ledge at the right, Lee, the lilac fledgling, looks on; below them, a Coneroll, a brown pinecone with a green sprout and a gray scribble cloud over its head, stands on a long white ledge in front of a fluffy cloud
People also ask: where do the bubbles go?

Many hands, one game

Tirralee plays with a keyboard, a gamepad or a touch screen. Two players can share one keyboard: Tirra on the arrow keys with / to blow bubbles, Lee on A, D and W with F. On a phone, the left thumb walks and the right thumb jumps and blows. The touch zones are bigger than the buttons you see, so a thumb can slide between them without looking. Hold the phone upright, and the game asks you to turn it: “Everything is bigger that way, and your thumbs have room for the buttons.”

Tips that leave when you’re ready

Nobody reads a manual before a jump, so the game teaches as you go. In the first level, one short line at a time shows up over the room: how to walk, how to blow a bubble, then “Now pop the bubble: just touch it!” A tip goes away the moment you do the thing and never comes back. On a phone, it says “Tap ◯ to blow a bubble,” and on a keyboard, “Press X to blow a bubble.”

The first two levels, the whole meadow, are free to play in your browser at tirralee.com. The full game is $4.99, paid once. More about the game is on the Tirralee page.

More about Tirralee