The closest analog to Lab X18 in Call of Pripyat' would probably be lab X8,
It's extremely mazelike, and I will warn everyone ahead of time: underground, there is a "wallhacking" Poltergeist: it can sense you and chuck shit at you
even through walls (i.e. it can control stuff beyond walls, not that the stuff itsself somehow phases through the walls). Off this thing
first or you
will not get far, trust me on this (I figured this out the extremely irritating and painful way back when I played through Call of Pripyat').
@T34G3: if you can get your hands on the
one Gauss Rifle in the game (unsurprisingly, held by a Monolith preacher at first), then it is ridiculously useful at times, though not as much as it was back in SoC (holy shit, pseudogiants go from being terrifying to target practise. Such a relief). Otherwise, AK-74s are a decent choice for a wepon in general, though as seaoflcl stated: go for something with a scope, all 3 of the guns he listed are good for this purpose. As for zombies, same advice applies to them as to everything else in these games:
you want to be headshotting them. If you're not, practise shooting at a precise target in-game until you can reliably do it. Call of Pripyat's controls are a
lot less clunky than SoC's, so there is no excuse to spray zombies with ammunition except as a last resort when you missed a headshot. Alternatively, zombies and zombified stalkers
will not recognise grenades and thus will not move away from them - as a result, it is fairly simple to insta-gib even a group of them with a couple carefully-thrown/launched grenades.
Thirding the statement that bloodsuckers aren't really terrifying. More just gross, really - though you can tell the developers were definetly trying for a Lovecraftian-style look when they designed their appearances.
Oh and btw Lab X-16 > Lab X-18.