Galaga is one of those games that I don’t really remember the first time that I played it… or really much about my early experiences with it at all. I can only assume that I have played it at some point during my formative years, since when I saw it later I recognized it.
I never really was able to figure out if there was a story in this game, all I know is that you have a lone ship and have to take it up against wave after wave of what appears to be space-bugs. You, in your ship have three things you can do: move left, move right, and fire some kind of anti-bug blaster.
The enemies, though get all kinds of special abilities. They can move forward, backward, left, right, off the sides of the screen and onto the other, all while shooting you with whatever weaponry space-bugs have. The thing, though, is that the weird green boss-bug things have this tractor beam where they can suck up your ship to fight on their side. The kicker is, though, that if you kill the boss-bug at just the right time you get your ship back, which immediately gloms onto your current ship doubling both your firepower and vulnerable area. Quite the trade-off.
I think I didn’t play this game very often when it was in arcades because I perpetually had a lack of quarters, which is a side-effect of having a single-digit age. So I mainly just had experience watching the attract screen and learning what point values the different bugs had, and reading my ‘arcade game tips and tricks’ books to pretend like I was playing the game inside my own head. Which was a whole lot cheaper.