Building a fully procedural otter game with zero assets

@fernmaker made a 3D game where you play as Rill, an otter pup sliding, skimming and skipping down a forest river.

Play Fernwake
prompts to build the valley
versions along the way
texture, model or sound files
for the whole game, in a browser

Build figures: Tesana build data. Size: the game's first load.

“I wanted a forest you could get lost in. The valley kept growing as I went: first the slide, then skimming, then the waterfall, and finally the sound of the river.”
@fernmaker · Creator of Fernwake

Fernwake is a 3D game where you play as Rill, an otter pup, sliding down a river through a small forest valley. You get around by sliding: drop onto your belly on a slope, pick up speed, and if you hit the water fast enough you skim across it like a skipping stone.

Timing matters. Jump right as you touch the water and you skip, a bit faster each time. You can twirl in the air, go over a waterfall, pop out of a pool and ride the rapids down to a meadow. Twelve sun motes are hidden along the way, and some you'll only reach with a good line.

What makes it unusual is that it has no art or sound files at all. Every tree, fern and rock, the otter's fur, the water, the light and the sound are generated by code when the game loads. The whole game is about 270 KB and runs in a browser on a desktop or laptop with a recent graphics card.

The idea

A river to slide down

Fernwake is a small forest valley with a river running through it. You're Rill, an otter pup who'd rather slide than walk.

Run to the bank, drop onto your belly and let the slope carry you. If you hit the water fast enough, Rill skims across it like a skipping stone, and jumping right as you touch down makes you go even faster.

Rill, the otter pup
Skimming the pool
The prompt that started it
Make a 3D game about an otter pup called Rill in a small forest valley with a river. Rill would rather slide than walk, so let me run to the bank, drop onto my belly and slide down, then skim across the water like a skipping stone. Make everything with code: the trees, the ferns, the fur, the water and the sound. No image or audio files.
@fernmaker

1 hour to playable75 versions to the whole valley

The build

180 prompts to the whole valley

Making a game on Tesana works like this: you describe what you want, Tesana builds it, and a few minutes later you're playing the new version. Then you say what to change and go again. Here's how Fernwake came together:

  1. StartThe first prompt
  2. 1 hourPlayable
  3. 15 daysThe whole valley
  4. 12 NovOut on Tesana

Tesana wrote all the code that grows the forest, the otter, the water and the sound, and it hosts the game online. @fernmaker decided everything else: what to add, what to change, and what didn't feel right yet.

Clip
From the grass to a belly-slide onto the water

Adding the skip took a single prompt:

@fernmaker's prompt
When Rill lands on the water while skimming, let me press Space right at touchdown to skip again, a bit faster each time, with a splash and a ring on the water.

Made by code

A forest with no art files

Everything you see and hear is made by code while the game loads. There are no image, 3D model or sound files:

  • Every tree, fern and rock in the valley.
  • Rill's fur, one hair at a time.
  • The water: the pools, the mist from the waterfall and the rapids.
  • The light, coming through the trees in shafts.
  • The sound of the river and every splash.
Clip
Past the waterfall, skimming down the river

Go over the waterfall, twirl in the air, pop out of the pool and ride the rapids down to the meadow. There are twelve sun motes hidden along the way. Some are on the bank, and some hang over the water where you'll only reach them with a good line.

Ferns, grown by code
Rill on the forest floor

Build stats

What it took

From the first prompt to the whole valley:

  • 180 prompts to build the valley.
  • 75 versions of the game along the way.
  • About 270 KB for the whole game: the forest, the otter and the sound.
  • No art files: no textures, models or audio.
Down the river
Rill in the meadow

Fernwake is out now on Tesana. Go give it a try.

How the valley grew

Each new version added something to play with. Once Rill could slide, the ideas kept coming: skipping across the water, a waterfall to go over, light through the trees, a sound for every splash. Nothing in Fernwake had to be drawn or recorded, so any idea that could be described could end up in the forest.

  1. 28 Oct

    The idea

    An otter pup who'd rather slide than walk, and a forest river to slide down.

  2. 1 hour in

    First slide

    Rill belly-sliding down a grassy bank. The heart of the game was there from the start.

  3. Day 5

    Skipping stones

    Hitting the water fast turned into skimming, and timing a jump on touchdown turned into skips. The slide became something to get good at.

  4. Day 9

    A whole valley

    The river got somewhere to go: over a waterfall, through the rapids and down to a meadow, with sun motes hidden along the best lines.

  5. Day 12

    Hearing the forest

    The river, the waterfall and every splash got their own sound.

  6. 12 Nov

    Game live on Tesana

    Ready to play in a browser, with nothing to install.