Galaga '88 (renamed to Galaga '90 for a later Turbografx-16 US port of the game ) was made in 1987 for the Arcades. The logo says Galaga in a golden font with a silvery '88 below it.
The gameplay is similar to the original Galaga, but with some changes: One notable change is that Galagan Commanders ("Boss Galaga") can now capture double ships. If you free a double ship from the grasp of the evil Galaga Corps, you will earn a triple ship, which was newly created for this game. It was one of the most popular Galaga games from Namco, staying close to the original formula.
The gameplay is different from the original Galaga in some ways: It adds dimensions, big Galaga Corps ships carrying small ones, obstacles to destroy and different bosses in different dimensions.
To advance through the dimensions the player must get 2 blue capsules first and then complete the bonus stage. When the bonus stage is completed 2 blue capsules will rise to the air, opening the portal to the next dimension and awarding the player 10,000 points, 20,000 points , and so on.
Capsules were also added to Galaga '88. There are 2 kinds of capsules, a blue one and a red one.
These capsules are used to advance to the next dimension. They can be obtained by destroying certain obstacles or by destroying the 2 galagas that make a giant bug which fly left and right going down. The only way to advance to the next dimenson is to get 2 blue capsules. After the challenging stage is done the 2 blue capsules will rise in the air, opening the portal to the next dimension and awarding the player the amount of points every 10,000. If the player has only one blue capsule then it will fly into the air and disappear. On Galaga '88, there are a total of 5 dimensions. On Galaga '90 there are a total of 4 dimensions.
These capsules are used to upgrade your ship. If your ship is a single ship, it will become a dual ship. If your ship is a dual ship, it will turn into the new triple ship which can fire three bullets at the same time, but will become a dual ship again if hit by an enemy or shot by an enemy. You also get 500 points when you get a red capsule. If you collect a red capsule while your ship is a triple ship, you only get 500 points.