I could write an essay on why HL2 and the Episodes are some of the finest games ever made and embarrass the original, but I don't want to, so let's agree to disagree
I've already written a few essays on why they're some of the worst things to happen to shooter design in the past several years, as well as bad sequels to the original games (example: silent character is useless when the gameplay and NPCs already define him as a person--he might as well have a voice).
I would, of course, be
interested in an essay explaining why they're better than the originals, but I respect your desire not to do so.
The combat is littered with amateurish mistakes that distant it from Half-Life's original design. Majority of the levels are only redesigned aesthetically, and are otherwise room-for-room identical, with a handful of Half-Life 2 valve/physics 'puzzles' thrown in for good measure. The extinguisher effect was cool, and impossible without the flair effect ripped right from Episode 1.
I admire what they've accomplished, but acting like this is some tremendous overhaul and advancement of the Half-Life formula is a gross exaggeration.
Where I feel confident enough to say that I know Half-Life room-for-room, I continually find myself surprised by what comes next in Black Mesa. Quite a lot has changed (for instance, when you turn the power on in Blast Pit, you don't actually murder a guy who thought it was a good idea to hide on top of a generator for some reason, because he's now hiding in one of two control rooms at the top of the shaft). A ton of stuff has been redesigned to combat the "this doesn't make any architectural or logical sense" arguments people have made towards Valve games over the years. I certainly don't remember nearly as many secrets to discover throughout the game.
My main issue with the combat seems to be an issue of timing. Everything's faster. In the case of the houndeyes, it's a welcome improvement. With the bullsquids, vortigaunts, and marines, they aim and fire far too quickly. Vorts in particular need to be glass cannons. I do appreciate that they seem smarter (hunting down the player when he's out of sight), and find them far closer to a stimulating experience like FEAR's than something as dreadfully dull as Half-Life 2. The Combine and antlions are down there with Legendary's Werewolves as some of my least favorite enemies of all time, though the tedium of fighting them comes from the feeling of boredom I get when encountering them, rather than the tedium of having to perform an extra step to ensure they're dead.
I don't think I've come across any seesaw or "stack stuff/place it somewhere" puzzles from Half-Life 2. Can't remember if the "find a valve and plug it in" puzzle was in one of the Episodes or not, but I've come across it twice in Black Mesa, and it's a great improvement on what the original had done in those locations.
Maybe my opinion of things will change. I'm part way through On a Rail right now.
EDIT: Black Mesa's space feels like a real one. Combating its enemies feels... better. I know, rationally, that the AI is cheating (actually, I seem to be able to trick it into doing things, so maybe not), but when I play it, I find myself acting as though I'm playing against real opponents. I find them tricking me (one baits, another flanks), or, as I said, I find myself fooling them (the earlier-mentioned example of them waiting for me to come out of a vent, when I'd really worked my way all the way around them). When I back out of sight, they pursue me until they can make me dead. They're smart, and I value that. If I didn't have to duck so much, I think the only other complaint I'd have would be that my hitbox feels huuuge, since people can melee me from a few feet away. I love that I have to think when fighting these guys. I have to plan before taking one on. I have to
listen to see if there's more than one in the room. With a lesser game, like Half-Life 2, I just max the difficulty, walk in, shoot everyone, move on to the box with infinite rockets, have another unsatisfying boss fight, and repeat.
And, honestly, once I started treating them like real people, my acceptance of Black Mesa as a real space grew even more, and I remembered why I fell in love with Half-Life and OP4 half a decade ago. Basically, the Black Mesa team has focused on making this a better immersive experience, rather than a better gamey-type game. That, I feel, is the direction Half-Life should have gone in, because that's the framework the first game established. Scripted sequences and clever AI spawn placement helped convey the idea that this was a real 3D space. The environmental storytelling in the game ("SURRENDER FREEMEN!" anyone?) helps bring that across even more. The Black Mesa team has expanded on it. I find this a lot better than having an NPC walk alongside me, displaying obvious game routines, asking me questions about a past I never had (thus creating a character that may or may not be at odds with the persona I have established in my head), going through random level bits that barely make sense in context (this is a cave level, that is a zombie level...), all so the game can show me its pretty physics.
I value intelligent shooter play. I value player movement (the most important element of any good first-person game). I value virtual worlds. Black Mesa does this. It doesn't always do it flawlessly, and it's certainly rough around the edges (someone recently pointed out to me that the assassins use the same rigs as male characters, for instance), but it does Half-Life better than any Half-Life game since Opposing Force.
