Disclaimer: I have played only the campaign and not the original game from 1999. With that out of the way, let's get into my thoughts for this great and misinterpreted title.
RE3 is by no means a stand-alone game if you liked RE2 released a year earlier. This is a companion, part B, the other side to Leon and Claire's tale in the previous game. The events occur prior, during and after the events unfolded in the other game, only taking place very close by in the city while the T Virus outbreak is at its peak. In order to understand the scope and scheme of the paranoia that spread like wildfire across this fictional US city, you should play both the games side by side, or back to back as they are designed to be so. That is the reason why they time stamp events within the game with the date so that if we can use our brains a little better we can actually understand the timeline ourselves without referring to a Youtube video by a creator who has done just that. And secondly, you simply have to score this game on its own merits, and not compare the execution, tone, pace with a game released 21 years ago. If you want to experience identical feelings of that game, you can simply play that game because as I've heard, it still holds up for "real" RE fans. This game is a modern interpretation and telling of the same story, but with a different taste, a different set of clothes on the same body of horror. It does the creators discredit if you keep comparing their own game, with their own remake of that game, and point out differences to show one's weaknesses. I'm sure if they wanted them 2 to be that identical, they would've made it that way, it is their games after all. The modernisation works, in spades, with flying colours, only if you let it.
The protagonist for this game is Jill Valentine, a former S.T.A.R.S agent who apparently was instrumental in the events that took place in the first game. Backstories and lore of the universe aren't well explained here and you discover past events by reading letters and documents scattered throughout the levels. Right off the bat, that makes her more capable of handling a zombifying virus outbreak as she has handled it before and her personality, poise and confidence shine throughout, stark in contrast with that of a young Leon or Claire from the previous games. As a lead, as the person you can count on, she is the best of the 3 (or 4 as you will discover later). Because she is well capable of defending herself and a veteran of the situation, it wouldn't be wise to portray her as a weak scared heroine learning her trade to eventually become a lady like Lara Croft in the reboots. Capcom was wise enough to make this game about Jill's bravado in facing challenges rather than her character growth in the middle of the outbreak, as we saw with the previous game. Survival horror is still in effect, with inventory management and scarce resources forcing you to constantly think about your approach but in general, this game is a lot more about the action set-pieces, which is in part due to the hulking Tyrant Nemesis who stops at nothing from finding and killing Jill. Yet this is also the first drawback I noticed, as Nemesis' presence was too similar to the Tyrant in RE2, simply occasionally turning up to fasten the action until you reach a safe haven where he disappears only to threaten you again much, much later. His presence often feels like a reskin of the earlier Tyrant and it would've been much more memorable had his presence been more constant to make him feel like the main bad guy, instead of a tool sent by an unknown face to kill. But regardless of his involvement, the strongest point of RE3 is the narration and its cohesiveness, as there isn't any filler in its entire runtime of 6 or so hours. There is a constant objective which demands your attention and these games being very linear, you are constantly moving forward in the story. Yes, I missed the backtracking of the last game and the grinding of puzzles and opening doors, but that is because this is a different game with a different motive. Jill isn't a detective searching for clues or a saviour. She is out there in the middle of an outbreak trying to survive. All expositions come as a matter of fact, and it never feels Jill deviates from the main setting of the game, or her personality. It is a cat and mouse story where the cat just doesn't feel that effective in taking up the role of the main bad guy.
Along with the solid narration is the spectacular presentation. RE Engine might be the most photorealistic game engine out there and the game looks phenomenal. The character models, every detail with the lip movement during dialogues is spot-on gorgeous and the environments are detailed as all-hell. A lot of the survival horror and the general setting of desperation, urgency and terror comes from the environment and sound design which instil this feeling of a lone survivor in you right off the bat. Audio-visually this game has no competition and I'm here to break the news that Capcom puts the character models for the showcase as unlockables just to flex their muscles. This game can be played in one sitting, though I advise you against it for health reasons, without feeling jarred or any break in cohesion thanks to the excellent design and smooth gameplay which shows no surprises here and retains the exact same feel from the last game.
The other characters in the game are fleshed out well which make the story more intricately laid out. The other protagonist, UBCS soldier Carlos might be the typical do-gooder but his presence never feels out of place and his segment is there to fill a time when Jill was out of action due to *spoiler hidden* and plays well. Another drawback comes when he goes out of narration for the final third and his side of events arent shown at all, which sticks out like a sore thumb because of the otherwise solid storytelling. His chapter in the story doesn't have the gradual upwards curve in characterisation and self-discovery but that fits well with the timing of his appearance as a playable character (much later into the story) and the way his character is written into the story, as a soldier with a solid moral compass. While his might be the most un-RE chapter, it's welcome nonetheless as a novelty act.
Minor narrative disturbances aside, this is a solid game that ties directly into the other one as a Raccoon City duology with a different tone but the identical feelings of exhilaration and achievement. There are no changes to the gameplay and having just one campaign makes this a full-priced game with just 6 hours of story, something that simply cannot be justified. However, if you find a good deal for both these games, they are definitely worth playing and enjoying as a fresh new take on the original story of RE, with incredible graphics and audio design. And 4 characters with their own stories and personalities which add to the setting wonderfully.