Gyruss/NES walkthrough

Changes from the arcade

 * Two different control schemes are offered, as explained above. One operates like the arcade, allowing you to choose what side of the screen to travel to, and the other instructs the ship to travel clockwise or counter-clockwise.
 * In addition to the single shot gun, which can be upgraded to a double shot gun, there is also a powerful energy blast weapon which has limited ammo, and will destroy everything in its path, excluding certain bosses. Up to seven such shots can be stored by the player.
 * In addition to a weapon upgrade pod, other bonuses may appear between the space stations, including extra energy blast shots, a crash bomb which destroys every enemy not currently in the center of the screen, or an extra life. More than one set of space stations may appear within a single stage.
 * More planets are visited during the game, including Pluto, Venus, and Mercury, and then on to the Sun. Bonus rounds count as a stage, and there is a total of 40 unique stages before the game starts over from stage 1.
 * Aside from the regular enemy space ships, there are a few enemies which only appear en route to particular planets. Some of these enemies are unique to one planet, and others reappear during warps to subsequent planets.
 * The second warp to each planet involves the destruction of four enemy pods which rotate around the center of the screen, instead of clearing all of the enemies which occupy the center. The music for such stages is also unique.
 * Bonus stages include alternately colored enemies which release some kind of power-up or bonus when destroyed. These include escalating points which culminate in an extra life, or extra energy blast shots.  These bonuses will always appear on the direct opposite side of the screen from the player.

Game flow
The game flow for the NES and Famicom Disk System version of Gyruss is very similar to the arcade's. Every planet takes three warps, including Neptune (which still takes place first, before Pluto.)  Each of the three warps has a particular pattern to it, as explained below.
 * Three warps away:The first warp to a planet is not very distinct from a typical warp in the arcade version. Waves of enemies fly onto the screen in particular formations before settling into position in the center of the screen.  A few planet specific enemies may appear, but not many.
 * Two warps away:The second warp to a planet is extremely different, and features a new element in the game: enemy pods. Four pods rotate around the center of the screen.  These pods take several hits to destroy, and the stage is not complete until all four pods are destroyed.  Even though enemies fly onto the screen in the usual formation, the number that actually make it to the center is irrelevant, since the pods will continue to release enemies for as long as they are around.  More planet specific enemies will appear throughout the stage.
 * One warp away:The third and final warp to a planet starts out identically to the first warp: waves of enemies fly onto the screen in formation, and settle in the center. However, once all of the enemies are defeated, the player is presented with a boss battle that must be cleared in order to advance to the planet, and to the chance stage beyond.

Neptune

 * Unique enemy
 * Boss

Pluto

 * Unique enemy
 * Boss

Uranus

 * Unique enemy
 * Boss

Saturn

 * Unique enemy
 * Boss

Jupiter

 * Unique enemy
 * Boss

Mars

 * Unique enemy
 * Boss

Earth

 * Unique enemy
 * Boss

Venus

 * Unique enemy
 * Boss

Mercury

 * Unique enemy
 * Boss

Sun

 * Unique enemy
 * Boss