A serious question; did developers in the 90's simply not know things that we know to be good and true today (mutability can induce bugs, consistent naming is good, global state is almost always bad, huge switch statements bad, various code smells, etc), or were doing some of these things not efficient enough for the computers of the day for various reasons?

Like, there's definitely some smart thinking in this code, but there are also several things that just floor me. A 3000 line switch?

I also see this in JavaScript from the 90's. Everything global. No patterns. Its just weird.

Really nice review of source for a truly classic game.

It's cool that we have source available and even better that it's so easy to digest with the help of the review like this.