So, I played the game for a while now and judging by reviews in Steam, it's quite controversial, so I'm going to carefully explain how I perceived it and why.
First off, I wouldn't really trust reviewers, who played the game less then an hour and then go "the game is unplayable!!!11". No matter if you're a fan of the old game or not, judging an entire game by 30 minutes of play is complete nonsense. The game is definitely not unplayable - it does have its quirks and, from what I read, some technical issues (of which I encountered none during 8 hours of play), but it plays like any released game should play. Now, to the individual aspects.
Graphics
At first I was very skeptical at the art style. It's simple, unimpressive and reminds rather of portable games than a PC release. They did release the game for the PS Vita, so that might be where that comes from. The longer I played the game, though, the more I started to get used to and enjoy the graphics. It might not be new or innovative, but it's quite possible anything else could have been an overkill when thinking of what the old game looked like. The climax was reached when I got Undine and got to see how detailed her re-imagination in 3d was. Her icon was very neat and detailed and her 3d-model quite convincing. The mana spirits are very iconic for this universe and I think they actually did a nice job at the 3d representation of them. I only have 3 of them so far, so I have yet to see the others.
Overall the 3d models and textures are very neat, tidy and true to the original. There is sort of an album for monsters and characters in the menu and their models can be viewed and rotated at any time. Almost everything looks the way it's supposed to look: The Rabites do look cute and the Nemesis Owl's eyes are now going to haunt my dreams.
What I'm kinda neutral towards are the animations. There's nothing unique about them - they're neither good nor bad. Also, the mouths don't move when people talk. Although since the mouths are textures, it probably would have looked like South Park if they did. I will mention, however, that it's noticeable they put some thought into the animation, since Popoi has a different lie down-animation than the other two to match her mischievous personality. Although it also might have been there in the original already. Furthermore: Dancing traders remain! \ô/
What I don't like are the spells' effects. While I don't remember how they looked like in the original SoM, I know what the looked like in SD3 and they could have made to look much more awesome than right now. The way the mana sprites appear when casting a spell is great, but the effects themselves are pretty boring.
Gameplay
Now, I'm not sure how much of it is due to source material, so I'll just judge it by how I perceived it from a new game and apologize in advance for possibly deconstructing the original SoM, since I don't know which things were taken directly, and which ones reworked.
The combat is, to say it mildly, meh. For today's standards the combat is artificially delayed, unresponsive and sometimes random. If one character hits a monster, often subsequent hits from party members will miss for no reason. And even if they do hit, their hits are kind of registered a second or so later and cause the monster to be "stunned" one more time, again not registering hits from other characters. It's just very very unpolished combat with a lot of room for improvement.
The dumb AI doesn't really help here either. I remember getting Popoi as the second party member and going into the forest with her while she is at Level 1. She was constantly being killed by Porobins despite having a ranged weapon herself. I was trying to face-protect her as much as I could but there are some areas, where the archers attack from both sides, which resulted in her being two, or three-hitted. It got better when she leveled up a couple of times until the same thing repeated after getting Primm with Level 1.
Some other things are questionable as well, like for instance the weird slimes that you keep missing for some reason while they make more copies of themselves. I tried different weapons since I thought it might be a "right-tool-for-the-job" scenario, but nothing really worked. You needed to get lucky and land a good hit while there is only one or two slimes to finally end the combat. They could have been just ignored, but that would mean unfinished business and the feeling of leaving the room incomplete.
What I did like was how items and spells work now. They don't freeze the game anymore, but instead only freeze the character they're used on for the duration of the animation. This allows a party member to throw a candy onto another party member, while continuing with whatever task at hand. Although it sometimes results in the characters taking a hit during the animation, dropping to 0, playing the "me dead" voice over and transforming into ghosts, and then suddenly being healed and be alive again after the healing animation finishes. So, yeah, this is kinda weird.
Some other "minor", yet quite annoying issue is when buying new equipment, you have no way to see how the new gear will affect your stats. That results in sometimes buying unnecessary equipment and having to sell it again.
Overall the gameplay is something that takes a lot of getting used to. As soon as you stop "wtfing" every time you miss for no reason, it becomes okay.
Sound
The soundtrack has been great so far. There is an option to switch between the original soundtrack and the remade one, but I have been playing with the remade one so far and I like it. I guess this is very subjective though. If it's well done, I don't mind taking modern versions of 16-Bit music in favour of the old one. There was one instance, though, where my ears would have yelled at me, if they could, and that was the Dwarf Village. But from what I gathered, even dedicated SoM lovers hate that soundtrack.
The sound and VOs, however, are something, that takes getting used to. While the VOs themselves are mediocre at best, I have to give credit for actually providing
EVERYTHING with a VO. Not only dialogues, cutscenes and main character have a VO, but also every NPC you can encounter, which pretty huge considering it's a Mana game. And while I'm usually the quality>quantity type of person, in this case having everything voiced is great. It's not like there are great VOs in japanese games anyway. Persona 4 english VO was bad back then, and modern anime and japanese games like Blade & Soul have the same type of mediocre VOs as well. The only really good one that comes to my mind right now, is the english version of Avatar - The Last Airbender, but yeah, different medium, different studio(s).
What was surprising, though, is hearing the dude's voice from The Walking Dead Telltale game as Gemma. I really liked him in his Lee role, but he was also in Mincraft - Story Mode, where it was meh. Here, it's just weird and I don't know if it's because his voice doesn't match the character, or because I recognized the voice, or just because he's not doing a great job because reasons. At least I'm pretty sure it's him, I have yet to google it.
Also, I gotta mention that a variety of dialogues between the main characters have been added, which appear when staying at an inn. I though they were part of the original game as well, but when watching someone stream the game, I was told they're new.
The SFX are fine, but I wished the monsters had more and distinct and memorable sounds they make. Currently, they are either completely silent or making as few noise as possible.
Thoughts
Okay, well, I think I pretty much covered everything.
Having read a bunch of Steam reviews, they range between players , who are not familiar with the original hating the combat and people, who actually find the VOs great, so there is no telling how someone perceives the game. There were people saying "I waited 25 years for this and this is shit", which I actually find amusing since they're basically saying that the moment they finished the game, they thought to themselves "Sooo.... when's the remake coming" and proceeded to think that for the next 25 years. Sometimes people just don't realize how dumb they sound, but hey, if not for dumb people, we wouldn't have anything to laugh at, eh?
The argument "they ruined the game" is invalid as well and to those people I'll say the same as to the people claiming the Game of Thrones series ruined the books: No it didn't - the books are still there, go read 'em, no one forces you to watch the series if you don't like it. Watching it despite not liking it only rewards Benioff and Weiss for doing the poor job they did. The same goes for Square Enix. So, simply out of respect for SoM fans, I won't say it's a worthy remake, but I will say, however, that it's a decent attempt at one.
For me, it was like "this is meh and this is bad, and I don't like this", but the longer I played the more captivated by the game I became. I don't know if it's because I'm generally hard to disappoint, because my expectations to everything and everyone are usually pretty low until proven otherwise, or because Square Enix did take something seriously for once. In any case, currently I'm glad I purchased the game and I'm enjoying it and looking forward to continuing to play it and to see what else it has in store for me.
I would not recommend buying the game if you're...
...a huge fan of the original game and aren't able to distance yourself from it in any way
...a huge fan of the original game and want to keep the warm and fuzzy feels alive
...not familiar with the original game and like combat full of action
I would recommend buying the game if you're...
...a huge fan of the original game, but are able to let your judgement not be clouded by it
...a fan of the Mana series and are able perceive it as a standalone game
...never played SoM, but are generally a fan of JRPGs
...not familiar with the original game and like a good story