None of the enemies will attempt to collide with you while they appear, but they will shoot at you (at the default difficulty setting.) Learn to draw their fire to one side of the screen, and cross over to safety once they begin to fire.
There are no container objects, like crystals, to obtain blue warp capsules from. If you wish to advance to Dimension 2 by Stage 4, you'll have to wait for two of the blue goeis to combine and dive to the bottom of the screen. Shoot the first one that forms three times to obtain a warp capsule from it. You must do this on this stage as well as the next in order to advance.
Whether you started with a single Fighter or a double Fighter, it's a good idea to allow your Fighter to get captured and advance all the way to a triple Fighter. Be aware, however, that by doing so, you will have no extra lives remaining (under the default settings) until you earn enough points for an extra life. Be sure to shoot the Boss Galaga that is capturing you just once to damage it if it's not damaged already, to make reclaiming your Fighter easier.
The special enemy of Dimension 1 are the balloon-like Dons. Most of the time, when you shoot them, they explode harmlessly into fireworks. However, on some occasions, they break apart into four baby enemies which drop straight down to attack you. If you manage to destroy all four before the leave the screen, you will be awarded bonus points.
The enemies appear in the same order as the previous stage, except that they always appear in pairs instead of a single, line, and every pair is lead by two large escorts. Each escort is worth 600 points if you manage to destroy any of them. Once again, none of these enemies will try to dive into you, so you only need to dodge bullets.
As explained above, if you wish to reach Dimension 2 by Stage 4, you'll need to wait for two Goei to combine, and destroy the first one that you encounter in order to collect a second blue warp capsule. If you make it to Stage 3 with only one capsule, you will lose it at the end of the stage and be forced to start your collection over.
Remember that capturing a capsule renders your Fighter invincible for just a few seconds, so you can put your Fighter at risk collecting the capsule, as long as a threat does not reach your Fighter before the capsule does.
If you already have a triple Fighter, there's no need to save any of the Boss Galagas, so destroy them as quickly as possible.
This is the first bonus stage of the game. In bonus stages, 40 enemies will appear on the screen in different waves. They will not attack you, and once they leave the screen, they are gone for good. Your goal is to destroy as many enemies as possible. If you destroy all 40 enemies, you will receive a perfect score bonus.
Ten Hitodes will appear, five from the upper left, and five from the upper right. They drop down to the bottom, never crossing the middle of the screen, and spin around in circles before flying back up to the top of the screen. Destroy one side as they drop down and circle, and destroy the other side before they fly all the way back up.
The second wave is the same as the first, except that the enemies fly up from the bottom, spin around, and then drop back down before escaping. Shoot them in a similar manner.
The third wave is identical to the first.
The fourth wave is identical to the second, except that four of the enemies are Boss Galagas, and must be shot twice before they are destroyed.
After the bonus stage is complete, if you managed to collect two blue warp capsules in the first two stages, they will rise up from the bottom of the screen and tear a whole in space which allows your Fighter to be transported to Dimension 2. Otherwise, you will remain in Dimension 1.
