The game takes place within a gigantic spaceship which has virtually infinite capacity because of its ability to manipulate time and space. The player must deal with enigmatic creatures called EVOL, which consist only of pure energy and need to keep themselves in capsules in order to maintain their existence in the world.
All of the characters in the game are designed to resemble microscopic organisms, both in their appearance and their quick, tricky movements. The player's ship undergoes over 10 types of transformations throughout the game, each with offensive and defensive maneuvers specific to their design. The sound effects used are minimal, but different types of sounds are used according to the type of shots or their speed. A sound resembling a long scream results when the player's ship is hit and returns to its weakest evolutionary state. The game's designer, graphic designer, and music composer, Tomo Furukawa, would go on to become the vocalist of the band Guniw Tools.The game controls like a regular shoot-'em-up: A and C shoot bullets, B drops bombs; there is rapidfire. However, unlike regular shoot-'em-ups where weapons are upgraded through powerups, your ship "evolves" to survive situations and get past obstacles. Evolution occurs with the Evol (small faces with an E on them) and B-Evol (darker Evols). Each pickup adds a new evolution state to the list. After a particular amount of time, one evolution wears off and the next evolution is chosen. The DNA powerup does provide a more permanent weapon upgrade, but will merely just make the existing weapons stronger. You can hold up to nine DNA powerups.