5 was great until you started to get kidnapped randomly. I’m out of reach on a silo, no one can get to me, then I somehow get whacked over the head.
Same with malaria in 2 - as a single mission it added some flavour but then quickly got annoying and just got in the way of the good stuff in the game.
2 had some really good stuff - if they revamped it building on some of the things it did well and fixing the enemy spawning, making the weapon degradation less annoying (or preferably just removing it as it didn't really add anything) and as above with malaria it would stand up well still today.