About

Neon Amoeba is a free browser game made by Zarsh Inc., a small software company. It runs in any modern browser with nothing to install and no account to create.

What it is

You play a single cell in a culture dish. You move it like a slingshot: pull back from the cell, let go, and it shoots the other way. That is the whole trick. Learning to aim in reverse, and to use the bounces off the glass, is what takes a player from level three to level forty.

The campaign is sixty levels deep. Each level asks for five to eight pieces of food while red cells drift in from the rim. Along the way your cell evolves through thirteen forms, from a single cell to a whale, across five eras of life. Eating makes you bigger, and a bigger cell is easier to hit, so every bite has a cost.

The forms and the creatures in the dish are based on real animals. The field guide explains each one, and where the game simplifies.

How it was built

The game is a single HTML file with no framework and no outside code libraries: a canvas, about fourteen thousand lines of plain JavaScript, and a service worker so it keeps working offline. Every sprite is drawn at runtime. There are no image assets in the game itself.

It is covered by more than five hundred automated checks. Some run in a simulated page, others in a real browser at desktop, phone and tablet sizes. Deliberately breaking the code is part of the routine: a suite that cannot detect a fault it was written to catch is not worth running.

What it costs

Nothing. The game is free to play from end to end, and its boosters are bought with biomass you earn in the dish. No ads are shown at the moment; the privacy page will say so when that changes. If paid packs of biomass go on sale, bought biomass is kept apart from earned biomass, and only earned biomass counts on the board. Runs helped by boosters carry a mark on the board.

Who made it

Zarsh Inc. builds small software products alongside its consulting work. Neon Amoeba began as an experiment in how much game fits in one file, and stayed one.