Galaga '88/Stages 15-18

The next four stages of the game take place in a sector of space where the great Bosconian wars took place many years ago. As a result, it features the remains of the Bosconian war bases in the background, and even contain some of the space mines which were left over from the battle.
 * Stage notes
 * The container object of the next few stages are the space mines left over from the Bosconian wars. They only require one shot to destroy, and the first one you break will release a blue warp capsule.
 * These are the first stages in which the waves that precede the formation may contain six enemies in each squadron. As a result, two of the enemies from each squad will dive bomb you, for a total of four diving enemy attacks.  Be prepared to shoot or dodge these enemies as they target your current location.
 * Galaga '88 enemy tombow.png In the following stages, zakos may transform into Tonbos (shown left). They fly across horizontally, and then drop down to the bottom of the screen in pairs.  If they reach the bottom, they will loop back around before making one final drop to the bottom.

Stage 18
In Dimension 2, the fourth bonus stage features an enemy that bears a passing resemblance to a hamburger. The enemies in this bonus stage are much more choreographed to the music. There are quite a few moments when single enemies dance individually across the screen. Be prepared to react at a moment's notice.
 * 1) Ten Hamburgers, five on the left and five on the right, will descend diagonally from the top, cross in the middle of the screen, curve out to the edges of the screen and up to the top, then wiggle back and forth to the bottom.  They cross at the bottom, climb all the way back up to the top, cross once more, wiggle back down to the middle before performing one last loop and exiting through the sides.
 * 2) Ten Hamburgers, five on the left and five on the right, fly in from the sides to the middle, double back to the edges, then fly diagonally upward, crossing in the middle.  Then they bounce along the top and gather near the center.  They loop down and meet in the middle again before climbing up.  The wiggle down the middle, and do an about-face, climbing upward, gather breifly in the center before splitting back up and exiting through the top.
 * 3) The third wave is identical to the first.
 * 4) The fourth wave starts out identical to the second, although it contains four boss Galagas among the Hamburgers.  However, when they reach the top of the screen, they don't join in the middle for very long.  Instead, they drop down to the bottom of the screen before performing a series of loops on their own sides of the screen that bring them higher up, and exit through the sides of the screen.

Stage 18
In Dimension 3, the fourth bonus stage features Green Babbits. Throughout the stage, they will make large sweeping curves, stopping occasionally to gather together very briefly before continuing on.
 * 1) Ten Green Babbits, five on the left and five on the right, will descend from the top and immediately cross over.  They drop down to the bottom of the screen, and they make wide sweeping waves back up to the middle.  They curver outward and then cross again in the middle.  They cycle back up and down two times before exiting through the sides.
 * 2) Five and five Green Babbits appear from the upper corners, approach the middle, and then immediately double back and staircase down to the sides.  Then they quickly drop down to the bottom, before bouncing around along the bottom, and making their way back up the middle.  They cross over, curve outward, and the cross over again higher up.  They make a loop, curve up, and then make their way off the edges of the screen.
 * 3) The third wave is identical to the first.
 * 4) The fourth wave starts out identical to the second, although it contains four boss Galagas among the Hamburgers.  However, when they reach the bottom of the screen for the second time, they perform an extra set of loops, one in the middle, and then more just off-center, before escaping through the sides.

Stage 15

 * Specific stage notes
 * As the first opportunity to play in Dimension 4, you must now deal with Kans. These are extremely tricky enemies to deal with.  They cannot be destroyed when they first appear, or when they are resting in formation.  The only time they are vulnerable to attack is when they are diving down from the formation.  Even when they drop down, they can loop around and deflect your shots.  When they are in formation, they block all of the enemies above them.
 * At the end of this round, if you manage to destroy the very last enemy before it escapes, you will be rewarded with a rare pink Triple Fighter capsule.

Stage 18
In Dimension 4, the fourth bonus stage features Ga. Unlike many bonus stages, only single groupsof Gas travel across the screen at one time. You only have to deal with two groups when you reach the Boss Galagas at the end.
 * 1) Five Gas appear from the right, wave up and down as they cross to the left, then curve upwards back to the middle.  They wiggle down a bit before wiggling off to the left.
 * 2) The second wave is the mirror image of the first.
 * 3) Five Gas appear from the upper left and staircase down to the middle.  Then they perform a figure eight downward and back up.  They move up and then right angle to the right, and then staircase their way down and off the screen.
 * 4) The fourth wave is the mirror image of the third.
 * 5) The fifth wave is identical to the first.
 * 6) The sixth wave is identical to the second (a mirror image of the fifth).
 * 7) The seventh wave is identical to the third,  but with six Gas.
 * 8) Two pairs of Boss Galagas appear from both top corners, and travel diagonally down to the center, before quickly breaking off and staircasing to the side.  Then they travel horizontally to the middle, and loop upward.  They bounce up to the top of the screen and perform several loops, before arcing outward to the top, and off the sides of the screen.