Figured I'd chip in on this (rarely ever posted, regular lurker, mate of @leicsmac and been chatting about the game elsewhere with him recently).
I got hold of this game around Easter time and have been playing it regularly since. The original is my favourite game of all time, so I've been excited about this for years. I guess that means that I've also set myself up for a big fall if the game turns out to be rubbish.
I haven't completed the game, but I am a fair way through it. So far, I'm very happy with what I'm seeing.
The stuff that you'd know and remember has been widely respected. The familiar characterisations are strong, and some have been raised to make them more interesting (see Jessie or Rude). Without wanting to give too much away, there are elements added to the storyline. It has been expanded. To me, none of this has felt forced and all has been welcome so far. Whether someone who is unfamiliar with the original game would appreciate that expansion, I couldn't say. It occurs to me that a lot of characters have been introduced, some familiar and some not. But then those characters can quickly disappear again and won't reappear for a long time. Where I am in the game, I know that another character is probably about to get introduced. I can imagine someone new to the game going "Not another bad guy I have to remember. How many is that now?"
The gameplay has been good. I've been through the ordeals of playing Final Fantasies 13 and 15. The latter had decent gameplay, although suffered from being about a non-singing K-pop band with underdeveloped storylines and personalities. However, in this remake the battle system is quite similar, albeit with the additions of materia and one or two elements from FF13. Square Enix do seem to have learned from their mistakes on this front. It's not perfect - you really have to keep an eye on your HP in the tougher battles, while quite a few of the lesser battles can be overcome just by whacking the attack button and then healing up afterwards - but it's decent and the best the franchise has come up with for many years.
As for negatives, there are certain things that don't work so well. The additional characters are more miss than hit. Some are just downright annoying, and I'm left thankful that they are unlikely to have any real impact on the storyline. The humour is also rather hit and miss. The original had really wacky humour at times, and sometimes this doesn't translate so well into a more 'realistic' setting. For instance, I've just been through the Don Corneo experience and that felt a bit forced and stodgy. (In fact Wall Market in general feels to me like it's ground the gears a bit.) Sometimes things get a little childish or teenage in ways, although I might appreciate it more if I was still that age myself. I also didn't get the chance to suggest that Aerith might be the slum drunk. There is still humour in it, but generally it has to be found in either other places to the original, the interactions between the main characters, or simply the joy of seeing a familiar very minor character or line being remembered and represented, such as a Sector 7 guard inviting his co-guard to go and see Loveless with him.
I see above that Leicsmac has said that some purists are not keen on the ending. I don't know what this might be, and I'm trying to avoid seeking out other opinions right now; I've fallen into that kind of trap before and hit unwanted spoilers. I've tried to avoid talking of the significant differences here, but I will say that the alterations that have been made to the original storyline are changes that I welcome, and frankly I think are things that probably needed to change given the world we live in now as compared to that of the late 90's.
So for me - so far, so good. Reading back, I feel like I've been picky above, and not properly representing how much I've been loving this. It has been an old friend brought back to life in a bright and shiny new way. The original storyline and characters have (at least so far) been respected. It's clear that the brains behind it are the same ones who made and properly understand the original. I just hope that they don't get too clever for themselves and mess it up at the end...