Bubble Sort

Sorting colored liquids between glass tubes sounds straightforward until Bubble Sort proves otherwise. The puzzle starts simply enough — a handful of tubes, a few colors — but the arrangements quickly become genuinely tricky, demanding that you think two or three moves ahead before committing to anything.

The core mechanic is deceptively clean: liquid pours from one tube into another only when the colors match at the surface. That single constraint transforms what looks like a casual activity into something closer to a logic puzzle with a time-delayed payoff. Getting a tube to run a single clean color feels genuinely earned.

Difficulty climbs steadily as more colors and tubes are introduced, and the margin for error shrinks. There's no timer pressuring you, which lets the challenge stay cerebral rather than frantic — the real tension comes from realizing halfway through a move sequence that you've painted yourself into a corner.