Fishbowl

the fish needs water. pull the pins in the right order.

A goldfish gasps in an empty bowl. Every level is one contraption of shelves above it, and one order of pins that fills the bowl: the stones down the slide first, the mud out its door, the cat splashed off before its shelf drops.

Each pin holds something up; pull it and whatever it held falls. A slanted pin is a slide to wherever its low end points. Water scares a cat it touches, and so does a falling stone. A stone in the bowl cracks it, and mud browns the water it touches. Fill the bowl past its line with no cat left. Eight levels, one new thing each; a fail replays the level.

Concepts: gravity, cause-and-effect, order-of-operations.

An interactive you play with one thumb, on Wundr.