Wrote a guide of sorts for Reddit's r/KingdomHearts. Thought I'd post here too for anyone who might need it.
So, I've played about a week's worth of Kingdom Hearts Unchained Chi and I've got to say that I love it so far. Here are some things about the gameplay so far for people who don't want to play the Japanese version but want to know more about it and for players of the Japanese version who need a guide of sorts.
General gameplay
The main story quests stop at stage 200 so far with a coming soon label on the next few stages. Doesn't take very long to rush all the quests.
Event quests so far have been dailies where you gather ingredients. More types of events will eventually be added.
Every quest (bar Raid Boss fights) have 3 challenges you can complete to earn you avatar coins and mythril shards (the only way to get mythril shards)
Leveling your character up (with LUX) unlocks more possible costumes to customise your avatar with. These costumes come with avatar boards where you need to unlock nodes with avatar coins.
Your avatar maxed out at level 200. The game's been around for 8 days or so and there are already a lot of people at max level.
Avatar boards allow you to increase your max HP, AP and deck cost.
Keyblades general.
So far, there are 5 unlockable and usable Keyblades in the game. They've all appeared in a previous game so far but they have upgraded forms that have not been seen before.
Keyblades start out with only 3 medal slots available. As you upgrade them, you'll unlock more medal slots (up to 5).
Keyblade medal slots can boost medals equipped to certain slots according to their type
Keyblades need Orihalcums each time to go up a form. They're only received from the first time you complete every 25 stages. Since at this point in time, there are only 200 stages in the main storyline quests, you can only get 7 so use them wisely. You'll be able to upgrade 2 Keyblades to max and unlock form 2 for 2 more Keyblades.
Leveling ingredients vary from Keyblades but they all use a general catch-all ingredient which are Mythril. There are 4 rarities for Mythril just like the main games. Shard, Stone, Gem and Crystal. They're really rare drops from rare chests in story quests. You can get a lot of them from the Monday daily quest.
List of Keyblades.
Starlight (Basic keyblade) - Starter Keyblade. No focus on type. Final form boosts magic type on slots 1&5, speed type on slots 2&4 and power type only in slot 3. It's the most balanced Keyblade but boosts elements the least (up to only 1.4x at Keyblade level 20)
Treasure Trove (ロックスプレンダー lit. Rock Splendor) - Dwarf Woodland Keyblade. Power type focus. Final form boosts power type on slots 1, 3 and 5 at 1.4x, 1.6x and 1.8x respectively when maxed at level 20. I maxed this one first because I had more power type medals at the start.
Lady Luck (ラストリゾート lit. Last Resort) - Wonderland Keyblade. Speed type focus. Final form boosts speed type on slots 1, 2 and 4. I haven't been able to unlock the final form of this and the next 2 Keyblades because I'm not able to get anymore Orihalcums.
Three Wishes (デザイアーランプ lit. Desire Lamp) - Agrabah Keyblade. Magic type focus. Final form boosts magic type on slots 2, 3 and 4.
Olympia (パワーオブヒーロー lit. Power of Hero) - Olympus Coliseum Keyblade. I'm stuck at the first form for this Keyblade and so far it only boosts speed on slot 3. Know nothing else.
Partying Up
At the start of the game, you'll be asked to pick between 5 union factions. They are Unicornis, Anguis, Ursus, Vulpius and Leopardos. You can only join parties comprised of people who have joined the same unions. So if you want to play with friends, make sure you join the same union.
The game has a ranking system for individual and parties and each rank session lasts a week where you will get a rewards depending on where you end up at the end of the week. You're ranked according to how much LUX you gain in the period.
Individual ranking pits you against individuals in the same union however, party ranking puts your entire party's LUX earnings against every other party in the entire game.
Raid boss fights Raid bosses appear randomly after you complete a quest (any quest, even event ones). They get stronger each time you fight them. The different raid bosses I've seen so far are Darkside, Guard Armour, Trickster and Behemoth. I've only seen one rare boss so far and it was a golden Guard Armour. If you fail a raid boss fight (which you probably eventually will since they take you out in 1 hit (13k damage) soon as you give them a chance to, you can resume the fight at the cost of very little AP (negligible even) as long as within a time limit. Each raid boss only sticks around for a maximum (so far) 7 minutes. Raid bosses give you a heck of a lot of experience even if you fail the fight.
This part I'm not sure but party members can get a chance to take our a raid boss you've encountered only when you've failed it on the first try.
Character Medals
Character medals have 3 distinct types and adhere to the scissors/paper/rock strength and weakness. Green is Speed (strong against blue but weak against red), Red is Power (strong against green but weak against blue) and Blue is Magic (strong against Red and weak against green).
Characters have abilities that consume ability gauges in battle. Hold and slide a character medal while in-battle to activate their ability. Abilities range from a high damage single hit type to medium damage 15 hit combos.
Character medals range from 1✩ (bronze) to 6✩ (gold). They correspond to the browser version's rarity rating of Normal, Normal+, Rare, Rare+, Special Rare and Special Rare+.
Unlike most mobile games where you can only upgrade a character once (so you have to keep rolling the hatcher to get the higher rarity straight away), KHUx medals can be upgraded all the way from 1✩ to 6✩ but doing it from 1 is quite masochistic.
Medals need to be at max level (differing depending on their rarity) before they can be evolved to the next rarity. You'll need a few for-evolution medals that can be acquired from daily quests (Power on Tuesday, Magic on Wednesday & Speed on Thursday). Merlin, Fairy Godmother, Yen Sid and Fantasia Mickey can all be acquired from Friday's daily event quest.
Level up your medals with Huey, Dewey and Louie medals that you get from chests. They also come in a variety of rarities. Leveling medals cost Munny and get exponentially expensive the higher your character medal is so level up with lower rarity ducks at lower levels and higher rarity ducks at higher levels to avoid going broke all the time.
Fuse your medals with Chip & Dale medals to boost attack and defense beyond their max. They'll appear as +number on their stats page.
Fuse your medals with Scrooge McDuck medals to let that character learn a skill. Skills I've seen so far as Attack Up S(or is it 5, I still can't tell) and Guard Up S(or 5).
Lastly, you can fuse your medals with Cid Highwind medals to reduce their cost (deck cost).
Coliseum The Olympus Coliseum challenge quests option is unlocked after completing stage 130. The Coliseum is a series of 3 battles per stage and they get much harder as you progress. Completing a stage nets you some coliseum coins you can use on the coliseum board to unlock Cid, Chip, Dale and Scrooge McDuck medals.
Completing a stage in 1 turn on all battles allows you to access the next 10-ish stages. Normally you would have to clear the stages 1 at a time. Clearing the hardest stage of the 10 unlocked ones will get you the rewards of all the stages you've skipped.
Proud Quests Proud quests were added to the game on Monday the 14th of September, 2015. There are 9 quests in total in each of the 3 types. The quests can be found under Event Quests on the Quest screen. You can get an Orihalcum from the easiest Power type Proud Quest allowing you to upgrade another Keyblade!
I've probably missed some stuff out so if you have any questions, feel free to ask!
p.s. I was wondering if I should put out a list of quest challenge requirements. I'll do it if you all want it enough.