the only classic RE I never made any headway in, probably because the ammo system is kinda nuts and tremendously strains your already limited inventory.
So I'm giving out mad props to anybody who did beat this, I hope to join you guys before the year 2030.
The ammo system was awesome.
If you mix A/B like 6 times it'll give you
way more handgun/shotgun ammo than you need.
But the true power of that system is mixing A/B together to get C gunpowder and then mix that to get a shitload of Freeze-rounds for the Grenade Launcher. Once you have those Nemesis becomes pretty trivial.
(And I lied, I just remembered
another mandatory Nemesis fight and that one is timed, but if you have freeze-rounds at that point you should be pretty safe to get past it)
Edit 3: Okay, there's
three mandatory Nemesis battles, but they're super obvious when you can't run away and thus have to battle him.
according to gamefaqs, he gives different parts every time you kill him?
Yes, but until you do the Mercenaries grind to 999999$ to get the Infinite Ammo reward to slap on your shotgun/Magnum it isn't worth doing that. While he gives you a powerful Handgun (the first two battles) and the Terminator 2 1887-style sawed-off shotgun, they aren't really needed to beat the game.
spoiler (click to show/hide)
He'll also give you ONE infinite ammo box like the Merc mini-game does, but you have to beat him like 8 times to get that.