The game plays like a combination of the classic Asteroids and Geometry Wars. The player controls a round spaceship that has a limited amount of health and must shoot asteroids and other flying hazards before they collide with the spaceship.
By default the player uses the mouse to move around the screen, and the WASD keys to aim the ship's fire. There is also a control scheme for dual analog sticks, similar to Geometry Wars' controls. The player must coordinate movement and firing to avoid being hit by asteroids and other hazards.
The player starts in the center of the screen, by default firing continuously. A small number of smaller asteroids fly around, mirroring Asteroids. To score as well as to progress, the player must destroy these asteroids. As the game progresses through the levels, larger asteroids begin to appear, followed by gigantic asteroids and finally more hostile enemies. The first actively hostile enemies simply gravitate towards your ship, and are easily dispersed. However soon the player finds periodic red asteroids that come in large single-file groups and fly directly at the player, requiring maneuvering away from them while firing backwards at the oncoming line of asteroids. The enemies get progressively harder and more numerous as the game progresses, including ones that look like a planet Earth with a half dozen circling moons.
Damage isn't instantly fatal; there is a health system indicated by both a heads-up display component and the size and color of the ring surrounding your ship. The smaller and redder it looks, the more hurt the player is. Damage does however have another downside: depending on how much damage the player has taken, their weapon may be downgraded by several levels, decreasing their survivability in later levels by a good bit.
The game has a powerup system that increases the strength of your weapon, adding either faster rate of fire or more streams in a linear progression, heals you, or shoots 8 shots in a circle, destroying anything in their path.
The game also features a number of achievements which unlock a bonus game, Crack!
Graphics and Sound
The game is 2-dimensional, and the screen constitutes the entire game. It is stylized to evoke the spirit of vector shooters like Asteroids, with simple straight-line or circular borders on objects, fake afterglow, and fake scanlines, though these effects are often exaggerated and completely misrepresented. In later levels it crowds the screen with excessive numbers of enemies, asteroids, and explosions to the point where it is difficult to keep track of any one object.
The sound is exaggerated as well, producing thunderous crackling explosions as enemies are destroyed, often becoming a continuous rumble as more and more enemies appear.
Crack! (Unlockable Bonus Game)
Gameplay is similar to the default Echoes, except that one hit kills and the player must shoot the rainbow asteroid to gain score, while avoiding all of the smaller asteroids that are released by the rainbow asteroid while it is being shot. The rainbow asteroid also constantly tracks towards the player, so they must keep moving if they want to survive. Multipliers can be achieved with successive hits on the rainbow asteroid. Once it is destroyed by whittling it down, a new one appears. Graphically it is much more similar to Asteroids, with the only color coming from the rainbow asteroid and sparks, with no scanlines.