So Persona Q really is a good game and I think it's going to be the quirky RPG this year that a lot of people who don't normally play these games might like. However it does throw a lot of stuff at the player so let's look at a few things I wish I'd known earlier on and that people who haven't played previous games might be blind to.
Persona Q is it's own game but it's also a crossover game, not just is it the Persona 3 and 4 characters crossing over but the Etrian Odyssey and Persona teams crossed over on it. Not totally or anything, but If you're a fan of the Persona series music there are lots of songs from the recent entries in this game and whatnot.
Etrian Odyssey is a series for the Nintendo DS/3DS in which you navigate mazes in a first-person perspective all the while drawing in a map on the bottom touch screen. Persona is a series no RPG fan can claim ignorance of but it didn't really get popular until the more recent games came out and rebranded the series as a unique mix of time management/social sim and dungeon crawler. EO is carrying the flag of old-school RPGs from the Wizardry era with Persona being emblematic of modern games with thoughtful design choices.
So first tip is to learn who these characters are. If you haven't played the previous Persona games they're all new to you, but really I'm talking about how the characters work in battle. Some characters like the Persona 3 main character, P3MC, are more magic users and shouldn't really be judged against characters like Chie who are much more front-line physical fighters. You need to build a party you like and it has to have several characters on the front line and several in the back. Yukari, who uses a ranged weapon and spells for offense as well as healing, is a definite back liner but characters like Aigis can really go either way. More info.
As you take your team through the dungeons you want to make a good map. However, if you don't want to worry about this much there is an auto-map feature that can help you out. The game automatically fills the map in a bit, but there isn't nearly enough info. Exploring the labyrinths will open up shortcuts, lots of shortcuts, and you can move around way more quickly if you know where these are.
The other big thing you'll notice in dungeons are the glowing, yellow power spots. I like to call them P Spots. Anyways you harvest materials from these areas. However eventually a message will pop up saying "you feel like the power spot is stronger, but also more dangerous" which means you might get a rare material next attempt or a fight where the enemies go first. You can get the good materials without having to deal with this risk-reward scenario and never tempt your fate but it's worth noting.
The last thing you'll notice in a dungeon are the FOEs. An FOE is a big monster who you can see on the screen that generally blocks your path. The bulk of your dungeon crawling is going to be finding ways around these guys since they will generally wreck you when you first come across them, especially if your party isn't balanced, but they drop rare materials that get you great gear and much stronger personas than anywhere else in their dungeon. They're also a good source of experience.
If you've played Etrian Odyssey before this should all be pretty familiar stuff, but the influence of Persona changes things greatly. Persona Q has no skill trees so trying out different party members is much more free. While people who aren't in your party during battle don't get any experience beyond quest rewards that give everyone experience the ability to just stick a great persona on a low level character means it isn't that hard to level up your alternates or an entirely new crew if you decide Teddy and friends suck as a party.
On the Persona side there are lots of changes. You can't change personas mid battle, but everyone can now have a persona equipped. Personas no longer give resistances naturally but an HP/SP boost that comes back at the start of every battle so even if you are running around with zero SP you'll have extra health and magic for every fight. I can't stress enough how important this is and to make sure your characters with stronger, more expensive spells have personas that allow them to cast or act at the start of a battle. Magic personas generally give equal HP/SP boosts with physical personas giving much more HP and little SP.
Persona fusion is still a mix of inheritance rules and stuff, but also some skills just can't be passed on. Every unique skill, basically, and any sort of null/absorb skill. This means that you won't be running around with super powerful units like in SMT IV, and that you'll use a good persona for longer than you might expect.
So each character gets several skills naturally due to their main persona's growth, but there are also these little blank spots you'll notice. These are for skills from skill cards. Every persona has a skill they'll give and this is a big part of building a great party. Once you open up the option to have a battle navigator and a labyrinth navigator you can work on making sure these characters have skills added in that are useful to their job and really help you out. As well in combat it can get old having to keep fusing certain skills for a character and this can be a way to keep from having to use up valuable skill slots on personas as you get more and more useful skills.
Another great addition is the sacrificial fusion. Take two personas you're not using and destroy them to give loads of experience to another. It can help you level up personas with skills you want to "card" or to make personas into better fusion fodder. I think the best way to do this is to go back and fight FOEs you can handle. They always give a persona as a drop and they're always higher level.
This game has a high encounter rate compared to most games released currently, but with the sacrificial fusion the game is never really grindy and you can escape battles to your heart's content.
Last few tips: always bring a Goho-M to escape a dungeon. Later you'll get a non-consumable item that will keep you from having to buy any more, but you need one of these guys. As well have some items to remove binds and ailments since for some reason it's always the character with the skills to remove these things that gets taken down.
Check in on your navigators every so often and make sure they have skills on their personas that will help you out. Fuuka is more of a healer and Rise is pure support. I like using Fuuka in battle because I can free up turns for actually fighting which builds up the leader bar. The leader bar is sort of like a limit break that lets your main character use skills without wasting a turn. With Fuuka I can heal whenever the need arises but if I had Rise she would make a lot of interesting changes too. Use these skills whichever you go with they're lifesavers in the tougher fights.
Unlike Persona's "All-out attack" system Persona Q uses something called boosts. If you hit a weakness or score a critical hit your character gets boosted and their next action expends no hp/sp and goes first in the turn order. If enough of your team mates are boosted you have a chance for an "All-out attack" but it's not a given like in Persona. This means you can keep a strong physical attack on your magic users and try to get them to score a critical to use their expensive skills without burning though precious SP or use your physical attackers boosted turns to lay down buffs and debuffs that might not usually want to burn SP on.
While you will always get materials for strong gear from FOEs another option is to take out regular enemies in specific ways. There are a handfull of enemies with materials that only drop if they're killed in a specific way, like while poisoned or by a specific elemental spell. This is a list of the bad guys and how to get their drops.
So I hope this saves people a bit of trouble. It's a fun game with a unique battle system and flat-out hilarious dialogue along the way. Take your time with the game, it's really long. So long as you remember to change up your sub-personas every so often and to fill your map in with useful info it's a fun game. Seriously there are puzzles I couldn't figure out until I went back in and started adding more details to the map, as well you never really have to fight the FOEs. If you keep running into a particular one trying to solve a puzzle you might be doing the puzzle wrong.