Crater Arc

How it plays

CRATER ARC is a portrait one-finger number puzzle set inside a sleeping volcano on a tropical island at night. Your guide is Basso, a small basalt golem with amber seams and a palm-leaf scarf, and every caldera is a race against your moves: cool every glowing magma stone before the moves run out.

Control is a single drag. Put your finger on a numbered stone and draw through its neighbours, up, down, left or right, while a bubble above the arc shows the running sum. Slide back onto the previous stone to undo a step. Let go at exactly 8 and the arc cracks; let go at any other sum and it simply fades, costing nothing. Sound, music and vibration can each be switched off in Settings.

The crater floor holds six by seven stones numbered 1 to 6. Every arc that adds up to 8 cracks its stones, the columns settle and fresh stones roll in from above. Magma stones glow among them, up to five at a time, and an arc that passes through one cools it; new magma stones roll in until the caldera's count is met. The first caldera asks for 4 magma stones with 12 moves, and every caldera after it asks for more of both, up to 18 magma stones and 23 moves on caldera 30.