Echo

What it is

Echo is a tile puzzle for the browser. You guide Squeak, a bat, through a cave to her nest. Each turn, moving one tile or waiting, costs a flap. Three turns after each of your steps, an echo repeats it. The echo collides with nothing and collects no crystals, but it does press plates.

Plates open the doors that carry the same symbol (circle, square or triangle). A door stays open while all of its plates are pressed, by Squeak or by an echo: think about where you will be three turns from now. In the Ice Vault, ice makes you slide to the end of the stretch for a single flap. In the Belfry a twin echo also follows you, six turns behind, and some doors need several plates at once.

With a finger or the mouse

With a finger or the mouse: tap toward where you want to go and Squeak takes a step, or drag and let go. Tap on Squeak to wait. Undo and Restart are two buttons under the board.

With the keyboard

With the keyboard: arrow keys or W, A, S and D to move; Space, Enter or the period to wait; Z to undo and R to restart. Escape or the P key pauses the game.

Levels and stars

There are three worlds of eight levels: Grotto, Ice Vault and Belfry. Each level gives one to three stars: one for reaching the nest, another for also collecting every crystal, and the third for doing it in the fewest flaps. If you run out of flaps you lose the level; on Normal you can undo steps without limit. Your progress is saved on your device.

Difficulty

Each level you clear opens on Hard, where you can't undo, and then on Extreme, where par is also the flap limit. Each difficulty keeps its own stars.