Stack

perfect drops make it wider. greed makes it thin.

tap to drop a sliding block — trim or grow the tower

Each drop only keeps the width where the new block actually overlaps the one below it — a dead-on drop doesn’t just avoid loss, it grows the tower slightly wider, while an off-center one keeps only the overlap and sheds the rest. Line up too little overlap and the tower is over; the margin for error only shrinks, since the blocks keep getting faster.

Concepts: balance, precision.

An interactive you play with one thumb, on Wundr.