You control a ship that fires in four directions: up, down, left, and right. You must fly that ship down a tunnel full of strange alien creatures and ships in order to reach the City Of Mystery, where the legendary Gond awaits. You must watch your fuel meter and make sure you shoot enough ships to keep it filled; lose all your energy and your ship drops and is destroyed. There are five different sections that appear in the tunnels that challenge you to fly through:
Mountain Zone -- the first one you enter. Mist ships hover around in that zone and Harley rockets just blaze right through, firing shots. You can use your lasers to destroy them, but a better option is to use those Energize stations that pop up periodically. They will power up a shield around your ship so that, even with your lasers deactivated, you can just simply ram into the enemies to destroy them. This power only lasts for several seconds, so watch out when the power shield goes out!
Rainbow Zone -- where you'll meet dancing Ammo and Helm balloons that bounce up and down in that zone. (On the first level, the Rainbow Zone also appears after the Stick Zone and the Stripe Zone.)
Stick Zone -- where you'll again meet the Mists and Harleys, but there's neither enough space to dodge them nor any Energize stations to help you out. (On the second level, the Stick Zone appears after the Stripe Zone.)
Stripe Zone -- where you're given a group of stationary targets to destroy, with the occasional beam stations to knock out their shield. Here the Energize stations appear.
Bleak Zone -- where you'll face off with the weird Kemlus snakes which, although they can destroy you, they can also give you a free ride three times for added points. After the Kemlus, a storm of Romeda rockets will fall down upon you.
Once you reach the City Of Mystery, you'll meet the Gond who resides beyond a series of gates with small chinks for penetrating shots. The Gond will try to close you in fron the bottom and destroy you with his laser shots. Destroy him, and you'll get a bonus as you start the next level at the first zone.
Up until you reach the City Of Mystery on the first level, you'll be allowed to continue your game from the point where you lost your last ship.
The arcade version used a joystick and four action buttons arranged in a diamond pattern for firing shots up, down, left, and right. The home versions attempted to replicate this by having the control stick being pushed in the same direction that the player wants to fire in when the action button is also pressed. However, the tradeoff for this is that the player's ship moves slower than when it is not firing, so some skill has to be used in piloting the ship. The Atari 2600 version used the difficulty switches for selecting four kinds of firing options for the ship.
The musical tunes used for this game include the theme from Star Trek: The Motion Picture in addition to "Vultan's Theme (Attack of the Hawk Men)" from the 1980 Flash Gordon movie during the shield power-up sequence.