Turbo Pudding
Look at the picture at the top. Tirra and Lee are standing on a birthday cake: a candle in the middle, a top tier, a wider tier below it and a bottom tier under that. It’s the fifth room of Tirralee, and it really is called Birthday cake. When we started building rooms for the game, we gave ourselves one rule: every room is a picture from its world.
Here is how a room gets made, from a few lines of letters to a picture you can climb.
One screen, no scrolling
A room in Tirralee is a single screen, 32 tiles across and 24 down. That’s 4:3, the shape of an old arcade screen. On a phone, that leaves space on both sides for the touch buttons, so your thumbs stay off the picture. Nothing scrolls. You see the whole picture at once, and every critter in it.
Written in letters
We don’t paint the rooms in a drawing program. Each room is written as text, one line of letters for each row. A # is a solid block. A = is a platform: you can stand on it and jump up through it from below. A dot is empty air. The arrows ^, <, > and v are wind, which pushes the bubbles around. And a 1 marks where Tirra starts.
The trick is that we only write half. Each line has 16 letters, the left half of the room, and the game mirrors it to make the right half. The wind arrows flip on the way, and Tirra’s 1 turns into Lee’s 2. That’s why Tirra always starts at the bottom left and Lee at the bottom right, and why most rooms look like a butterfly with its wings open.
The critters are listed apart, by column and row, so a room doesn’t have to hold an even number of them. The Bird house has two Stomplings inside, two Chirpets on the ledges and a fifth Stompling who lives on the roof, all on its own.
Next to every line we leave a little note about what that line is. In the Birthday cake they read “candle”, “top tier”, “middle tier” and “bottom tier”. The Mushroom has a “cap” and a “stem”. The Ladybug has a “head”, then “wings and spots”. The Tulips have “tulip cups”, two little U shapes, just deep enough to sit in.
The picture still has to play
A pretty picture isn’t a room yet. It also has to work with the jump. A hero in Tirralee jumps a little over four tiles high, so platforms sit about four rows apart, and a hero needs two free rows above a platform to stand on it. The fall is slow and floaty, and you can steer on the way down.
Every room also has a gap in the middle of its floor and a matching gap in its ceiling. Drop through the floor, and you come back in through the top. So the two gaps always have to line up.
Every room gets checked
Before a room goes into the game, a checker goes over it. It looks at the size, the side walls, the gaps and the letters. Then comes the important part. It takes the game’s own run and jump code and tries every move from every spot where a hero can stand. Every critter has to be reachable. And there must be no traps: no shelf you can jump up onto but can’t get down from, because the walls around its ends are too close.
Our room editor runs the same check while we work. We paint walls, platforms, wind and critters on the 32 by 24 grid, mirrored by default, and the editor tells us right away if a spot can’t be reached. One button plays the room on the spot.
A clock for every room
Each room also gets its own dusk timer, the time you have before “DUSK!” comes up. It’s worked out from the room itself: 20 seconds, plus four and a half for every critter, minus a tiny bit for every room you’ve already climbed. It never goes below 26 seconds or above 50. The Daisy, with three Stomplings, gets 33 seconds. The Birthday cake, with five, gets 42.
Fifty pictures
The Tree has 50 rooms, plus the boss fights, spread over five worlds: the meadow, the woods, the rain, the clouds and the night. The meadow starts with the Daisy, the Tulips, the Mushroom, the Ladybug and the Birthday cake, then comes a Butterfly, a Honeycomb, a Rainbow, the Bird house and a Garden party.
Higher up you’ll find a Pine tree, a Hedgehog, a Campfire, a Frog, a Teacup, a Paper boat, a Hot-air balloon, a Windmill, a Sleeping cat and a Music box, among others. We won’t tell you what the very last one is. You’ll know it when you see it.
Climb the first ten
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.
