A little bit better than I expected and definitely not a bad game, but it has some issues that lower it for me.
TLDR This game suffers from poor mechanics, despite some neat ideas and good story.

Pros
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-The story is surprisingly very strong. I didn't anticipate enjoying it as much as I did, with some genuinely good twists and theming.
-Building a town is a neat concept.
-Shared experience removes the stress of having to carry a low level mon any time you want to change up the party.

Cons
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-The gameplay is stripped down considerably from other titles. The lack of a hunger system removes challenge. Lack of starters removes party variety for most of the game. You can only perform ONE MISSION at a time.
- The story is too easy. You get high level story additions early on, most of the bosses are fodder (the final boss is pathetically weak). You get a PP refill way too often in dungeons. No hunger mechanic, etc.
-Base building is a grind that isn't worth the rewards, mostly thanks to the poor mission system.
-PAID DLC. Locking content that is normal in future entries behind dlc is just scummy. Furthermore, this dlc is now unobtainable due to Eshop closure (although you can use certain alternative methods I am not at all suggesting...)
-(Worth Mentioning) Streetpass is dead in all but theory, so Streetpass related content is no longer accessible.
-(Uncertain, may be bias) The dungeon floor generations feels worse in this game compared to other entries. Like it is way more nonsensical and longer to traverse than usual.
-(Uncertain, may be bias) Text boxes and cutscenes feel way slower than other entries as well.

Personally I am just glad Super and DX fixed a lot of gameplay issues this game had (even if Super does it at the expense of the entire first 2/3s of the story)

If you can get past how repugnantly slow text scrolls, since there’s no speed option when playing natively, and even holding B to auto scroll it is still slow, which bogs the unusually tutorial infested earlygame down (seriously, there is a tutorial for getting sand tombed in this game), or how the game’s mechanics are simplified a lot, what with no IQ skills or hunger, as well as its reduced roster of Pokemon, which repeats quite often early on, there is a beautifully heartfelt story here. I think in spite of it being my least favorite PMD to play through, it has one of my favorite casts. The dialogue is extremely charming, and the cast on the whole feels like a large family who are consistently active in the story. There isn’t a single one who’s shafted narratively, and I really appreciate that. And though this plays the weakest, I think the PMD gameplay loop is fundamentally so solid that there’s no way I could dislike the game. It’s just. Terribly tough to sell someone on the earlygame, which is everything people accuse Gen 7 of being, and then some. And yet, once you overcome that hurdle, you’re rewarded with such a brilliant cast. I’m just not sure how to sell someone like that. “Keep playing bro, it picks up 1/3 in” is a tough thing to say, especially when the gameplay remains fundamentally simpler to other entries, and you will notice enemy repetition. But beneath that, you do have a beautiful story and cast elevated by a leitmotif-imbued soundtrack that pulls at your heartstrings. The replay made me like this game more. I understand its status as the “worst” PMD, and am generally inclined to agree outside of the original Rescue Team’s jank, but I’ll also call this game worth your time, just probably if you mod a text scroll fix.

[Dammit Larry, You're Hard to Love, But You're Harder to Hate]

Gates to Infinity is definitely the weakest game in the Pokémon Mystery Dungeon franchise due to its inconsistency in quality save for one notable aspect. Does this make it a bad game? Well, yes and no. For every good thing I can say about Gates to Infinity, I can point to an equally opposite bad thing.
- "Oh cool, the graphics are in 3D!"
- "But this makes the dungeons feel far less distinct, and characters far less expressive".
- "I love the fact that I don't have to worry about hunger in this game!"
- "But I hate having to navigate the dungeons in this game because the hallways and floors are much less interesting to explore."
- "I love that my party members get experience and eventually level up even if I don't bring them along on missions!"
- "But combat in dungeons is so awful because of the zoomed in camera that I can never even try to generate strategy when I approach a given room in this game."

Every time I think I can award points to Gates, it finds a way to immediately earn a demerit, but every time I think the game does something really really bad, I'm surprised at a cool decision the designers made. The plot is overly simple and reductive in its simplifications of tropes about friendship and trust that we've come to expect from the first two Mystery Dungeon games, but then it uses those predictable tropes to create a plot twits that genuinely surprised me. The dungeons presented a really interesting way to break up the pace of the mystery dungeon layout with the overworld floors, but then these same floors provided little to no challenge and were more or less abandoned beyond one or two dungeons late in the game (not that I particularly enjoyed these breaks in the gameplay, they really didn't fit with the gameplay loo I came to expect from mystery dungeon). The Paradise was ultimately an overcomplicated hub zone that I didn't find myself developing whatsoever just because the game made it nearly impossible to efficiently complete missions, but Post Town, despite being nearly pointless beyond flavor reasons, won me over as a genuinely comfy spot in a video game. And speaking of missions, I found myself really frustrated that I couldn't select many missions at once in the same dungeon (a clear attempt by the game to not allow you to grind), but then at the same time, I found myself feeling relieved that I was finally done with a single mission after 4-6 floors because I really really didn't enjoy the dungeon crawl with more than two party members (but also the game was definitely balanced around you having four party members at once which is cool UNTIL THEY START RUNNING OFF AGAIN). So between all these positives and negatives I sit here struggling to consider how I really feel about this game.

At this point in time, the only part of the game I can unequivocally vouch for is its soundtrack. Almost every piece of music in this game after the first few dungeons is simply perfect for its respective application. Dungeon themes are filled to the brim with explorative passion and capture the exact feelings of excitement, anxiety, determination, and dread one might feel when exploring places named "Forest of Shadows" or "Great Glacier". I am particularly fond of the musical leitmotif that carries through each Magnagate dungeon (Telluric Path, Kilionea Road and Tyrian Maze) as the same musical notes carry through each piece representing the mysterious ability to travel through the ley lines of the planet. Keisuke Ito absolutely knocks this soundtrack out of the park and makes even the most grueling, unpleasant dungeon crawls slightly more manageable. I had heard the soundtrack long before playing the game, and I found myself struck at just how much I could still enjoy the game having listened to the official soundtrack in a vacuum. There was nothing quite like being ejected from the mysterious Kilionea Road and finding myself potentially without a single reference point in the forest of Shadows, having only my instincts and the music of "Forest of Shadows" playing. What a great feeling.

I struggle to outright recommend this game to anyone beyond those who would care to play every mainline Pokémon Mystery Dungeon game. It has the weakest gameplay loop by far, and its story takes a lot of effort to really take seriously. While it might be the case that I am just too old for what is essentially a YA-literature piece, I just couldn't make myself care about the plights of Emolga and Dunsparce. But then again, I found Virizion's arc to be pretty interesting and I really enjoyed Espeon and Umbreon as characters, as simple as they were. Once again, the duality of Gates rears its two-faced visage. For every good there is a bad, and for every bad, there is a good. This is the Gates to Infinity experience.

Gates To Infinity is just... fine. A passable Mystery Dungeon experience, though it's shallow and disappointing as a follow-up to the excellent Explorers of Time/Darkness/Sky.

+ The writing is just as charming as Rescue Team and Explorers with fairly memorable characters. Highlights include Victini, Cofagrigus, Hydregion, and Quagsire.
+ The ending is handled very well with a presentation that's arguably on par with Explorers' heart-wrenching ending.
- Gameplay is generally dull and repetitive as many of the series' most interesting mechanics have been over-simplified or removed entirely.
- Building up Paradise is a great concept that just wasn't executed very well. The slow trickle of materials through jobs, on top of the new one-job-per-day restriction, makes job completion laborious and the buildings you create from those materials are almost entirely useless.
- The main story is ridiculously easy, to the point that I one-shot the final boss. This could be down to me playing as Axew though as it seems exceptionally powerful versus other starters thanks to its early access to Dual Chop.
- The game's text speed is Diamond/Pearl-levels of obnoxiously slow, making story progress a complete slog.

People seem to hate so much on Gates to Infinity -- and trust me I can see the obvious hurdles -- but it's a good 20-hour-ish game.

The story is great and definitely is on par with everything that Explorers put down. Side characters have semi fleshed-out personalities and backstories. There is an option to make sleep/totter/whatever seed farms which adds to the overall goal of your partner. It's very cute.

It's the extremely slow text speed, limited character roster and unwavering dungeon designs that make this game hard to get through. The first couple of dungeons and the final dungeons have the same layout and are all hallway spaghetti.

It's not as replayable as EoT/D/S but I had fun playing it nonetheless!

Definitely watch a playthrough if you are not as invested in the Mystery Dungeon saga but want to experience the story.