Placement puzzle · iPhone & iPad
You found an empty glass jar in the attic. Fill it with water, let the afternoon sun in, and work out who can live in it together — because once you pour the water, nobody moves again.
Four columns across three layers. Light falls from the top down, and every creature only reaches its own cell and the four beside it — so who sits next to whom is the puzzle.
Where duckweed floats. It needs more light than anything else in the jar, and it throws the deepest shade on everything underneath.
Home to the fish, the water fleas and the shrimp. The fish is the one exception to the four-neighbour rule: it swims its whole layer.
Algae, water weed and the dragonfly nymph settle here. Anything a plant above casts shade on gets less light than the layer suggests.
Nothing leaves the jar. Food nobody eats and waste nobody feeds on simply piles up, and a cell that piles too high clouds the water and ends the run. A balanced jar is one where every output is somebody else's input.
Each one takes something and leaves something. Learning the chain is learning the game.
| Species | Eats | Leaves behind | Worth knowing |
|---|---|---|---|
| Algae | Nothing — it needs light | Food | The bottom of the chain. Shade it and everything above starves. |
| Shrimp | Food | Nutrient | Reliable, undemanding, and the nymph's favourite meal. |
| Water weed | Nutrient | Nothing | Needs a fair amount of light, and shades the cells below it. |
| Duckweed | Nothing — it needs light | Nothing | Surface only. The hungriest for light, the heaviest shade. |
| Fish | Food, twice over | Nutrient | Swims its entire layer, so distance is no obstacle to it. |
| Water flea | Food | Nutrient | Fed well for long enough, it divides into a neighbouring cell. |
| Dragonfly nymph | Food — and live prey | Nutrient | Hunts shrimp and water fleas across its layer. Fence it in. |
Each chapter brings a better vessel. They line up on a shelf as you go, and you can put any one you have earned on the table.
A bare glass jar from the attic. Rinsed out and filled.
A pine frame you nailed together. Crooked, but yours.
A Victorian specimen tank from a junk market.
White enamel. The water looks clean enough to drink.
Hand-cut stone, as if carried up from a creek.
Vines over the frame, damp and thriving inside.
Black iron and brass, planted to the back wall.
Captured on iPhone. The room follows your own clock — morning sun, golden afternoon, a warm lamplit evening.
No timers. No scores. No energy meters. No in-app purchases, no advertising, no account, and no internet connection required — the whole game runs on your device. If a level has you stuck, the keeper offers to walk you through a working solution, one step at a time. Nothing else is asking for your attention.
Sunlit Jar