I'm going to write the first couple paragraphs as a review that can be read and understood by people who haven't played the game and will be entirely spoiler-free. After a point I'm going to dive into spoilers, but it will be clearly marked exactly where you should turn back if you haven't played the game.
999 has triple appeal to me: a batshit convoluted sci-fi mystery story, fun puzzles, and gruesome murders. I don't think I've ever played another game featuring this specific combination in a way that works this well. I've played/read other Uchikoshi visual novels (Ever17 and Remember11) which definitely cover the former, read the Dangan Ronpa let's play on SomethingAwful back circa 2012 which DEFINITELY covers the latter, played Professor Layton for a healthy dose of the second. But all three? In ONE package? This was a treat.
The highest praise that I can give this game in terms of writing is that I went into it with partial knowledge of the biggest plot twist, but it actually convinced me that I had it wrong until the true route, at which point I proceeded to punch myself in the face for doubting. Good mystery writing must find a balance between red herrings and legitimate foreshadowing, and make sure everything has at least some amount of payoff. There are a few things I think were under-utilized or even slightly unfair reveals, but the overwhelming majority of plot points were handled excellently.
I played the original DS version of the game, which is implemented so well and so specifically around the DS as a system that I have no desire to play any other version. One downside is that it does not feature flowcharts the way more recent similar games do, and therefore requires a lot of re-playing to piece everything together. That said - I actually think the game does a fantastic job of giving you all the information you need to make the correct decisions and to get the important endings. I don't think it needs flowcharts. It is very much designed around the expectation that you will fumble around your first couple playthroughs, and make certain realizations about what things must be done in sequence, and why.
I will admit that I did end up using a guide to get the last endings, though, and I don't begrudge anyone who chose to do so from the start. I had the right ideas but there were details I didn't have quite right and I was missing feedback that informed me I was on the right track - there could have been a little more indication when I was almost there, and what I was still missing, I think. But all of the pieces WERE present, and I definitely believe it is worth trying to find them on your own. It's extremely rewarding to view identifying the "correct" routes as their own puzzle to solve.
Overall, I think that the game design is very solid and the writing is excellent. There are a couple places where an additional nudge or hint may have been helpful, and there are a few reveals I don't feel had proportionate set-up to justify them (and some other plot points that could have been explored more); but in a game with SO many convoluted twists and reveals and such an EXCELLENT overall story, it manages the vast majority perfectly, and I liked it very, VERY much. I would recommend this game to all fans of sci-fi mystery, as well as people who enjoy puzzles. And murder. If you like all 3 of these things, then what the heck are you waiting for.
It is at this point that I'm going to start talking about spoilers, so if you have not played the game, I strongly advise against reading further.
I mentioned that I completely agree with the decision to not use flow charts, because the "flow" is not so much that every choice you make branches, but that you are definitely going to end up with a bad murder ending unless you make one of two sets of explicitly correct sequential decisions. And you can figure out how to make those explicitly correct decisions from trial and error when playing it blind. I tried to approach it as a branching flow chart at first, and that made it much harder to try and figure out until I changed the way I was approaching it... at a point, it becomes clear that Clover and Snake are important, and there are specific interactions that stand out given that:
Door 4: Santa hands you a clover.
Door 5: this is the only time in the entire game you get the chance accompany Snake.
Door 7: you get the opportunity to give Clover something.
Door 8: Clover asks you if her brother said anything of note to you.
Door 1: Clover, you know, murders everyone with an axe.
So the obvious conclusion is that 4-7 might change the outcome in 1, and that 5-8 might reveal something interesting if you get particular dialogue out of Snake.
I do still think it's difficult to get the actual endings on your own, though, even if you have figured that much out. 4-7-1 you must *also* follow the appropriate dialogue to trigger Seven's memory. Now don't get me wrong, I understand why the game wants to make sure you see this, as it's quite important. But unlike "obtain clover -> give to Clover -> she doesn't murder people", there is no obvious connection explaining why triggering Seven's memory should prevent Clover from murdering people. This is likely me just complaining because I Didn't Figure It Out (TM), but if there were an additional scene in the 4-7-1 route where it becomes clear that Seven's memory could potentially change the outcome, I would have absolutely no qualms with this. Additionally, if such a scene in fact does exist and I just missed it because I was skipping through dialogue for the 9th time, I'll rescind this complaint and acknowledge that I just wasn't paying as much attention as I thought.
Similarly in the 5-8 route, it is obvious that the safe is important, but "click on the safe twice after solving the room puzzle" still doesn't quite sit with me as fantastically intuitive game design. It has the same energy as how, to get the True End in Persona 4, you have to go to Junes but ONLY AFTER you've talked to everyone else. I tried to go to Junes too early and it didn't have anything for me, so I didn't come back. Sorry! No True End for you. I knew the safe was important, and I knew that getting some specific dialogue from Snake was important, but there didn't seem to be any clear indication that these two things were related or that it meant I had to click on the safe twice after solving the room.
(I actually thought, on my first playthrough, that during the "split up and search for Snake" portion I could return to the safe room and see if he was there, since Seven kept the doors open - but nope, there was nothing like that. I think that it would have been more intuitive to have an opportunity like that to show the game "yes, I remember the safe, let's go back there," but maybe the idea was to make this ending something you had to really go out of your way digging in order to find. I get what the intention was, but it's still not great implementation, in my opinion.)
All this being a long-winded way of saying "I don't think flow charts are what this game needed, I think it needed just slightly improved clarity on all the necessary steps to get the right endings and why you must take them." The clover from Santa was really obvious step 1, and giving it to Clover is equally obvious step 2. So I appreciate that the other steps were maybe not quite so obvious... but they could have been a little more clear, or at least, the cause-and-effect more evident.
(Also... this is just, completely a stupid thing to be upset about, but I REALLY WANTED the door numbers in the true route to add up to a digital root of 9. I think that in addition to context clues, if the equivalent of "4-7-1" which is the true end combination, was actually a sequence of numbers that add up to a digital root of "9" that would have been way cooler. Specifically, I point this out because I'm bad at math and at first I thought if you add the 5 from Junpei's room in the beginning it does add up to 9. It doesn't. I keep trying to bullshit a way for this to work and it just doesn't, and yes I am salty about it. The closest thing I was able to bullshit is that if you do add the 5, the total is 8, and the final door q is equivalent to 26 which would also have a digital root of 8, sort of, if you squint.)
At any rate, I thought it was interesting that instead of the endings being a series of branching paths from every decision you make, it is more a matter of messing around until you pick up on what very particular order you need to do to get it right. That was an excellent concept even if I have criticism on the implementation.
The one reveal that I have the most issue with is Santa's number being 0 (or 9; fundamentally the same, will get back to that point shortly). Or, well, allegedly. There isn't any actual confirmation one way or another, it is theorized that June's "6" is an upside-down "9" and therefore Santa's must be a 0 since they went into every room together.
I think the main take-away, the *actual* reveal, is that June and Santa always entered the same room. THAT is an important revelation. 6+3 is indistinguishable from 9+0 if they always go together. Especially after the "0" bracelet was revealed as "O": it casts doubt on the meaning of every number you've seen so far (which numbers are actually letters? 1=I? 5=S? 3=E?). Then at the very end, this sets up that the 9 door is actually meant to be a "q," allowing everyone to escape. That payoff, when you least expect it, in an unexpected context, was absolutely fantastic. No qualms with any of that- that was great.
But I'm still salty about the fact that Santa's bracelet, clearly reading 3, is magically supposed to be 0/9. Again, I'll get to the theory I'm most satisfied with (in fact, convinced by) in a minute, but having an entire game where literally everything obeys this internal logic and then having ONE (...or two) exception(s) really did feel a bit cheap. I did like the idea that since 6+3=9, effectively, June and Santa together are both indistinguishable from 0; but each of their actual bracelet values being 0/9 was one reveal I didn't feel was foreshadowed properly.
There is one explanation that I read after completion, however, that does in fact satisfy me. On one hand, I like the fact that this result is not given in the game at all and therefore the player is encouraged to come up with conclusions on their own. On the other, I'm still a little frustrated that it feels *completely* divorced from what the game gave us, and it's so much better than what the game DID give us that not at least hinting at it is going to make a lot of people miss out on something extremely interesting.
The explanation is thus: the string of digits from the bracelet code, the key to the safe as well as the coffin, 14383421, when multiplied by 9, gives the following:
Notice what is there where "3" and "6" should be.
I like this. A lot. Not only does it give significance to that initial string, which OBVIOUSLY must have some kind of relevance; but it actually in-the-text justifies the reveal behind Santa and June's real bracelet numbers. I am completely okay with their true values being different from their display values and having the "O" be a red herring here and only relevant with door q, but only if we have something like the above string, a completely DIFFERENT clue, hinting as to the true bracelet values.
I just wish that it was implied more in the text. I'm not even saying it needs to have been explicitly stated, but if there was any other point in the game - any other puzzle - where you have a string that you have to multiply by 9 to get a different answer, that would be enough. But as it is just "here's a string that's obviously important" and "9 is thematically important" are not, to me, sufficient for "multiply this string by 9 and get the hint that Santa's bracelet is actually 9" to feel justified.
It's really difficult striking a balance between "the game tells you everything" versus "you the player must figure out everything" that feels satisfying. I always like it when a mystery game DOES expect the player to do their own detective work, and rewards you for doing so. But this, arguably the most important reveal as it pertains to numbers, really REALLY needed just one more nudge in the right direction, so that at the end I can say "holy SHIT" and not just "....huh, okay I guess."
In every other respect, though, the game is fantastic. Its twists are built up and paid off. My favorite red herring is Alice/All Ice, because I spent the entire game being completely convinced Lotus was actually an ancient Egyptian mummy and only at the very end when I realized that was a cold trail, only THEN do we get a sexy mummy hitchhiking in the middle of the Nevada desert. That moment alone redeemed just about all of my complaints throughout the entire game. The foreshadowing/misdirect/reveal pacing in this game is EXCELLENT, which is even more impressive when you consider how many different reveals it has to balance.
I also appreciate that there are some... implications, from various events, that can lead the player to interesting and unconfirmed conclusions. Much like the bracelet thing in fact, but unlike the bracelet thing, these are not the literal actual most important reveal in the game, so I'm perfectly fine with the fact that they are ambiguous and left to the player to ponder.
The fact that Snake is blind and missing his left arm, from a "car crash", and in the operating room Clover is visibly upset and you swap all external body parts of the mannequins... except for the head and left arm.
The fact that Akane's narration describes everyone by identifiable clothing and distinctive physical descriptors, which people with prosopagnosia rely on to identify individuals. (Disclaimer - I don't remember whether the narration on the ID card puzzle on top vs bottom screen disproves this line of thinking or not. I just remember very pointedly how the narration pays such particular attention to clothing and other non-facial descriptors.)
The fact that Akane's bracelet is not removed after her apparent death in Submarine ending. The fact that she gives the same death monologue on 2 different endings. In fact, just about everything surrounding Akane and her fevers is worth thinking about, and from a couple conversations I've had, her behavior has drawn different people to wildly different conclusions.
I want to re-play this game someday to see if I arrive at new or different answers. I probably will. For now, my answer is "999 Good."
I have yet to play either sequel to this game, but I'm relieved to know they are largely their own stand-alone installments, because I absolutely love 999 as I have just experienced it: also as a stand-alone. It has an almost perfect blend of concrete in-game reveals + additional ambiguity for me to question. It has a twist that re-frames the context of everything you've experienced and absolutely brilliantly utilizes the DS's dual screens to tell two concurrent narratives. I've talked at length about the couple things I'm salty about, because it's easier to talk about what I didn't like versus what I did, as the list of things I DID like is about a mile long. If I didn't talk about it here, just assume I think it was dope. I'm only criticizing so much because everything else was so... PERFECT, that the things that WEREN'T perfect just stood out all the more.
To end off this admittedly rambly and all-over-the-place ""review"" I am going to say that the final puzzle being upside down was one of the most galaxy brain things I have ever seen in a video game. There is something about a puzzle that must be solved by the player PHYSICALLY changing something, outside of game mechanics, that is really poetic in this context. Akane is not at the wheel this time. It is Junpei. The top screen is finally the one you can interact with.
Putting aside the fact that it was very awkward to do this on an emulator where I couldn't rotate the window, I can't think of a more perfect climax to such an excellent game.
9 hours, 9 persons, 9 doors. Well those numbers are basically all bullshit, but that's okay, because the game is a 10 anyway.