The arcade game in the beginning comes from the epically long load times early disc reader systems suffered with. That's why Nintendo stuck with cartridges on the N64. Namco figured if you're trying to destroy the alien mother ship instead of just staring at a load bar you don't get as annoyed. It worked pretty well.

I played this game a lot. Like, a lot, a lot. It wasn't nearly as good as 2 and 3 makes both of them look awful, but I'd still go back and play this one fairly often even after I had the other two.

Speed runs and whatever other challenges I could think of.