Pouring a tile onto another tile of the same value merges them into a single tile of double that value, in the same way 2048 combines matching numbers. Two fours become an eight, two eights become a sixteen, and so on.

Onto a tube whose top tile matches your value, or into an empty tube. It is the same restriction as a water sort puzzle, with merging added on top.

Look for chains before you pour. A merge that immediately creates a tile which can merge again, and again, covers far more ground than several isolated merges. Pours that neither merge nor set up a merge are usually wasted moves.

Each level sets a target value — the GOAL tile — and you clear the level by merging up to it. A new drop lands after every pour, and the level is lost only when no legal pour is left. Undo, restart, boosters and a shop are available if a level proves stubborn.

The campaign has 40 levels over four worlds — Corner Café, Greenhouse, Glass Lab and Night Bar. Level 40 completes the campaign, and play then continues as an endless run on the same ladder.