imho the best way to experience advent is through knuth's cweb translation, because you can both play the game and then read the source code as annotated and narrated by don knuth. i haven't looked at the original fortran, but knuth says that his is a faithful translation. knuth's version was also proofed by don woods himself.

you need a TeX installation for this to work, but modern TeX distributions, like TeX Live, have cweb and pdftex available. for those who don't know cweb (and originally web) is a language on top of C, which lets you construct a narrative around your code. ctangle produces the c code, while cweave produces a tex file, which you can compile with pdftex and get a nicely typeset pdf with the source code and the narration.

  wget https://www-cs-faculty.stanford.edu/~knuth/programs/advent.w.gz
  gzip -d advent.w.gz
  ctangle advent.w
  cc advent.c -o advent
  cweave advent.w
  pdftex advent.tex

second best is to boot ITS simulator, so you can also experience the original attempts to minimize the work productivity effects. the original version, in addition to preventing save scumming, also had cave closure functionality during prime work hours.