I bought Alchemic Dungeons originally on 3ds and beat it each way to Sunday.
When DX came out with its expanded offerings, I got wrangled back in to the completionist autism.
Now here we are.

What I will mention:

Characters and Stats
Floors
Weapons and Tips

With DX, there are now 9 playable characters. Each character has stats pertaining to:

Health: As far as I can tell, this relates to your HP game per level.
Strength: Physical attack power. Separate from your ATK, but both are used to calculate damage.
Dexterity: Ranged attack power. Also, your arrow production equals half your DEX. May influence your evasion, as I have evaded attack without having any items that increase your evasion.
Intelligence: Magic attack power. Also, your wand production equals half your INT

As stated, these values are seperate from your ATK, DEF, and SHT. The latter three are directly related to your equipment. So, somehow, your STR+ ATK / DEX+SHT /INT + Magic ATK= your damage. I do not know the exact calculation.

Gaining levels gives a max HP gain, as well as at least a damage increase. Your stats do not gain at level up, but it does seem to boost your general damage output and defense somehow so that you stay somewhat competitive with the enemies around you. That said, you'll definitely need some Golden Apples and stat potions to survive deeper in the dungeon.

With regards to their stars on the player select screen, it seems that it works out to roughly the first two stars = 4 stat points, and every additional star = 2 stat points, and a hollow star = 1 stat point. For example, Witch, who has 5 INT stars has (4+4+2+2+2) 14 INT to start. There are exceptions to this rule though.A quick run down of each character:

* A note: I mained Elf and am predisposed to range attacks and buffing damage output to make a glass cannon, so my bias may be apparent. As well, though the DX version increased the drop rate for special items like Golden Apples, I find it challenging to up all stats together, so It makes more sense to buff just one or two.

*This advice is moreso for the Eternal Gallery, the final dungeon. The first 6 Dungeons (Level 0-5) are pretty simple, it is really 6-Alchemist's Lab, and 7-Eternal Gallery where you have to think long term.

Fighter:
HP: 3.5
Str: 3
Dex: 3
Int: 3
Skill: Physical ATK +20%
All around good guide. Not matter what you find, you'll do okay, although he is predisposed to physical combat.

Hunter:
HP: 2
Str: 2
Dex: 5
Int: 3
Skill: 30% chance arrows don't break
An alright skill, especially since if you use your bow 24/7, you'll be running out of arrows all the time. His skill+Bow enchanted with a stone of Vitality (50% arrows won't break) make a for good delving. But if you get Candradhus early on, his skill is redundant.

Dwarf:
HP: 4
Str: 4.5
Dex: 3
Int: 1
Skill: HP regeneration speed x1.5
I barely play him as his low INT actually makes it hard to inventory manage. I depend on wands for healing, and his low INT make them only slightly better than actual potions.

Witch:
HP: 1
Str: 1
Dex: 2
Int: 5
Skill: Magic ATK +20%
Using a staff has the added bonus of have a 3 range attack, and her high INT makes it so using wands often isn't a burden. If you wantsome added range, a bow enchanted with a magic stone of recharge so it is based off your magic attack is a good move.

Valkyrie:
HP: 3
Str: 3.5
Dex: 2
Int: 4
Skill: Evasion +25%


Ninja:
HP: 2.5
Str: 3.5
Dex: 3.5
Int: 2
Skill: 25% Critical
One of the two characters that come with character only specific items. The katana of the Shinobi, which has double attack, and the Shinobi clothes, which give evasion +30% The starting weapon and armour are alright, and each item can get an enchant slot if combined with an elixir.

Kinoichi:
HP: 1.5
Str: 2
Dex: 4
Int: 3
Skill: 100% accuracy
One of the two characters that come with character only specific items. Kuniochi cloths, which give 35% evade, and 6xKunai, which has double attack and are unbreakable when thrown. Another solid choice, as he equipment makes her quite versatile. The starting weapon and armour are alright, and each item can get an enchant slot if combined with an elixir.

Elf:
HP: 1
Str: .5
Dex: 4
Int: 4.5
Skill: Wand and arrow production +20%
Who I used to beat the Eternal Gallery. The production makes it so it is harder to run out of arrows and wands, and by the time I get to the lower levels, everything becomes a one hit KO anyways, so I don't bother boosting health or defense. Maybe someone has gotten that low with the Dwarf and Valkyrie and call them that boosting DEF and having more than 300 health gets you by, but I don't know.

Prophet:
Fighter:
HP: -
Str: 20
Dex: 20
Int: 20
Skills: Telepathy and 100% hit
Unlocked after beating the Alchemist's Lab, this character has top stats and skills, but 1 HP that does not gain at level up. He also begins with a ring of ressurrection. If you think you can get by by using Vitality potions, you're wrong. It would take 20 potions/golden apples to get a 100hp, and that ain't likely or the best use of those items. The telepathy is top notch, but the simple fact that any ranged enemy or traps or certain stat effects are a garunteed KO, if you don't careful or get certain equipment early on, you're not getting far with him.

There are 7 dungeons:

I will not provide commentary for any dungeon except for Level 6 and X, as they are relatively simple. I will point out how many floors are in each though. Beating each dungeon unlocks more recipes to make more items, but I cannot remember what is unlocked after each dungeon.

Level 0: Tutorial
Level 1: Phantom Forest - 7 Floors
Level 2: Lake of Mist - 13 Floors
Level 3: Frozen Mountain - 19 Floors
Level 4: Volcanic Desert - 25 Floors
Level 5: Untrodden Region - 31 Floors

Level 6: Alchemist's Lab - 37 Floors
The final floor of this dungeon is the Alchemist's Lab, the only boss fight in the game, and beating it provides the only tidbit of story as well. Upon entering the lab, you will have three directions choices:
Left: The Alchemist's Treasury (A room full of Mimic chests)
Right: The Tower's exit (A room full of 30+ enemies as a monster party. Only enter if you need the experience or potential items.
Up: The Alchemist (The boss fight. A special necromancer in a small room that teleports at random, can summon any monster at random, and can cast fire damage spells. Be careful, as he also holds a Philospher's stone, and needs to be beaten twice. The fight is actually easier in the DX version, as they have shrunk the size of the room and he seems to teleport less. Having throwing damage items are a benefit so you can hit him sooner before he has a chance to teleport.)

Level X: Eternal Gallery - 100 Floors
100 random floors that isn't as eternal as it seems. It is quite the slog though. Took me 3h45m to beat it.

*SPOILERS*
If you just want to know what happens at floor 100, it is a room similar to the crystal rooms of the previous dungeons, except instead of a crystal, there is a sushi on a table. Beating the dungeon unlocks nothing, and changes nothing in the game.

Stones:
Each stone has a use function, a weapon enchant function, and an armour enchant function. By looking at the recipe craft menu, you can see their use/1 of their enchant functions. From what I remember/researched, here are the enchant functions:

Stone of healing
Enchant weapon: heal 3 hp per attack executed. (It only counts on attacks against monsters, I don't know if it activates on a miss)
Enchant armour: Heal 3 hp per attack received. (Again, unaware of how misses are calculated.)

Stone of extra healing: Same as above, except 5hp

Stone of clearance
Enchant weapon: efficient against poisonous monsters (never used, not sure how it functions)
Enchant armour: 50% guard against status effects. Does not stack in the sense 50+50= 100%, but it might act as one 50% roll, followed by another 50% roll, for a total of 75% protection.

Stone of quick move
Enchant weapon: 20% double attack.
Enchant armour: 20% evasion. Just like above, 100% evasion does not mean you cannot be hit. I did get a Ninja up to 100% combined evasion, and he was hit fairly regularily (I had 30%+20%+25%+25%, which when multiplied would make my odds of being hit less than 1%, so maybe it only takes the highest percent

Stone of slow move:
Enchant weapon: 20% inflict slow move
Enchant armour: prevent slow move

Stone of confusion
Enchant weapon: 20% confusion
Enchant armour: prevent confusion

Stone of paralyze
Enchant weapon: 15% paralyze
Enchant armour: prevent paralyze

Stone of sleep
Enchant weapon: 30% sleep
Enchant armour: prevent sleep

Stone of mapping
Enchant weapon: 20% teleport
Enchant armour: 100% evade trap

Stone of fire
Enchant weapon: magic fire attack (Pretty good addition for dungeons 1-4, but the bonus damage is pretty poor in late deeper dungeons. Take critical hit damage over it any day.)
Enchant armour: 50% prevent fire damage. This one does stack, so enchant two pieces of armour makes you immune to fire. Better to use 2 stones of recharge to be immune to all magic though.

Stone of weakness
Enchant weapon: 20% weakness. (I have no idea how weakness works on a damage calculation level. I know when I am inflicted with it, attack about halves.)
Enchant armour: prevent weakness.

Stone of might
Enchant weapon: +5 to atk
Enchant armour: +5 to def

Stone of strength
Enchant weapon: 30% critical (Again, it doesn't seem to stack, it just seems to take the best one.)
Enchant armour: 30% counter damage

Stone of vitality
Enchant weapon: Weapon does not break when thrown (Never did a run where I tried this, so I can't talk to it.) For bows, it adds a 50% arrows will not break chance (Again, no stacking. I had a Hunter with Cadadrhus, and arrows still broke.)
Enchant armour: Regen speed x1.5

Stone of dexterity
Enchant weapon: 100% hit
Enchant armour: 25% evade (As stated, doesn't stack.)

Stone of recharge
Enchant weapon: Magic Damage. Instead of using ATK and STR to calculate damage, INT and Magic ATK are. Really useful for bows for magic users.
Enchant armour: 50% reduction in fire and magic damage. Does stack, so two of them makes you immune to Fire and Magic damage, making dragons, vampires, ghosts and pyrobirds a joke. A must have for the Prophet.

Philosopher's stone
Enchant weapon: Half your weapon's attack, rounded up, is added to your def.
Enchant armour: It says that "The higher the def, the higher the def bonus," but the one time I did it, it did not give a def bonus, but an attack bonus roughly half of the armour's def rounded up.

Stone of dark matter
Enchant weapon: Steal enemy life. Seems to be around 30% of damage inflicted.
Enchant armour: Adds the armour's def to your attack, and reduces your def value by half the armour's def rounded up.

Stone of bushido
Enchant weapon: 50% critical rate
Enchant armour: 30% evade

Stone of wind
Enchant weapon: 100% hit, 15% double attack
Enchant armour: 100% evade trap, 20% evasion

Stone of water
Enchant weapon: 30% poison, doesn't break when thrown, arrows have a 75% do not break chance.
Enchant armour: 65% prevent bad status

Stone of dragon
Enchant weapon: huge magic fire attack (never did, not sure how huge)
Enchant armour: 80% prevent fire damage

Stone of beast
Enchant weapon: 30% double attack
Enchant armour: 40% counter damage

Stone of gorgon
Enchant weapon: 25% paralyze
Enchant armour: prevent paralyze, sleep, and poison

Stone of demon
Enchant weapon: 30% confusion
Enchant armour: prevent confusion, speeddown, weakness

*For the use of stone of Gorgon, Dragon, and Demon, all enemies on the floor, whether you can see them or not, are afflicted. New enemies that spawn in are not.

Most items are pretty self explainitory, but I will just go through and make some general comments on certain items in each section. Again, this information is predisposed to the Eternal Gallery.

Materials:
When it comes to materials, you generally can skip over the rock/bronze level, and start at iron. Even then, I usually hold out for silver and save my iron for making gold/demonium. For arrows, it is pretty manageable to keep copper ones in stock, as copper drops fairly often. Save up silver and mythril arrows for later levels.

Food:
Nothing special. just a reminder that if your inventory is full, eat what is on the floor as you go by, and if there are seeds lying about, cook it before you eat what's lying about. And if there aren't any seeds to be found, it may be wiser to eat the cooked food and pick up the raw for cooking later (if your stamina is indeed that low, as you'll definitely find more seeds later.)

Potions:
They do what they say. If you got space, hang onto level up potions until after a level up or later game. The two you cannot craft are Elixirs and Demon Blood, which are used for:
Elixier: Drink to become invincible for I forget how many turns, or craft gold, Philosopher's stone, wand of invincible, or improve the Ninja's or Kuniochi's specialty equipment
Demon's Blood: Kill (really, if you drink it, you die, or whatever you throw it at), or craft demonium, or dark matter stone



Staffs:
Pretty straightforward. Just note that the Staff of invincibility is superior to just using a Philosopher's stone, staffs can be recharged with a stone of recharge, and a wand of level up is useless outside of the first few floors.

Weapons: Some weapons of note...
I never made a dragon slayer weapon, I don't know if it is 1 hit ko or just a damage boost
The trident is actually probably the best weapon, even better than Cadradhus. A bow with infinite arrows that you don't have to pick up afterwards.
Gold weapons are so marginally better than mythril they really aren't worth it.
Demonium weapons are, because enemy attack in lower levels is going to outpace your ability to raise your def, it seems easier to just crank your attack and kill them before they get you. (Again, I biased towards bows.)
Silver weapons are pretty keen, because you can enchant them with gorgon and silver is fairly common early on. By the time you start enchanting weapons with stones of might, they'll be just as good as mythril.
The beast claw seems cool, but you need to get it early so you can buff it strength early.
Cadradhus achieved early is a great weapon for anyone with high dex or int, as you can enchant it with a stone of recharge. It got debuffed from the 3ds version, which made arrows unbreakable, but 90% is pretty good as well.

Armour:
Just like weapons, mythril armour is much more economical than gold armour.

Shields:
Scale shield is good if you don't ever find a ring of resistance.
Aegis shield's 25% guard might be cool. I never used it with evasion to see if they would stack and give you 50% dodge.

Helmets:
Circlets are top tier, so you can have 2 rings at once. A circlet of Ressurection is alright, when you die, it reverts back to a basic circlet. It is a good idea if you're waiting for a better ring to drop.
A ring of resistance gives you the highest guard against bad status at 80%. In general if I get the chance to make a Circlet of resistance, I will, and enchant it with 100% trap evade to free up the enchant spots on my armour and my ring spot.

Accessories:
The Aqua Necklace is a waste of a scale.
The Zen mala necklace is like wearing a ring of critical and a ring of evasion at the same time
The hunting trophy is tempting, but just enchanting the bow with a stone of vitality works better because the accessory spot has to many better options.
I never tried to stack status down effects, like the Gorgan Eye with a Gorgon Weapon enchanted with a stone of paralyze, but I doubt the effects would stack.

General observations:

When you die, if you close the game fast enough, it won't save, and you can relaunch and redo your turn. Keep the game windowed and your mouse hovered over the close button, and if you die, quickly close the game.

In the options menu, turn off auto attack. Then you won't accidentally walk into invisible enemies and attack them.

This is just hearsay, but it seems like once you start a game, certain drops are preferred. As in, if you get one gorgon head, you'll probably get more. It may be by floor as well, because I have had certain monster party rooms drop three of the same ring.

The blue scale is one of the most useful crafting materials. It can make the infinte throwing Trident, its stone can +1 all your armour, and it can be used to make 65% bad status resist armours.

A ring of Telepathy is probably the best accessory you can get. It also points out Mimics and Treeants. Even if you use a stone of mapping, these creatures will not be pointed out. When in doubt, shoot trees and chests with a ranged weapon or throw garbage at them. Other hints include: if it is on another item, it is a mimic or treeant, if it is blocking a passageway, it is a mimic or a treeant, if suddenly a green dot appears on the map that wasn't there before, it is a treeant or a mimic. Trees and chest that are along walls have a higher chance of being mimics/treeants, but are not always.

On floors with wooden bridges insteada of hallways, you can shoot/throw weapons across the map. That means if you misshoot, your arrow is gone forever. If you have a ring of telepathy, you can kill enemies anywhere from anywhere.

I do not know if it is better to add +1 to a weapon or +1 to a stat. I've done runs where I have only boosted a weapon or only boosted a stat, and generally it doesn't work that well. I try and boost both. Early on I would boost stats to conserve crystals and to boost item production though.

Enemies with counter abilities interrupt double attack. Hitting a doll with double attack gets interrupted, meaning only a single attack occurs. This does not apply for bows or thrown items, which do not trigger counter abilities.

Some items that you should always have at the ready or ready to be crafted:
Always keep one crystal on you for emergency stone creation. It wouldn't hurt either to keep one golden apple available for emergency potion creation in case you need to make a new weapon or armour.

Stone of sleep. If you go down a floor and it turns out to be a monster party floor, this will be your best way to stay alive. A stone of might works well too, but I usually use both in combination. If you end up in this situation without a stone or stone of sleep, a potion of speed up can help you survive.

A potion of teleport is always handed to have. If you get cornered, or overwhelmed, it is a great way to get some breathing room to recuperate.

When you get deeper int he dungeon and you have your basic materials maxed out in your inventory, start wasting what you find on the ground. Too many crystals? Start making some stones of mapping.

How do you decide what to upgrade how? I generally wait for silver and mythril as an Elf. Since a helmet only takes one peice, I usually make it mythril, and make the weapon silver (added bonus because silver weapons can be upgraded.) Iron weapons and armour are a wise choice too, as they can be upgraded in fancy ways.

Hoard your iron, so you can make gold and demonium.

I usually focus on two stats, INT and DEX. DEX so I can have a bow, and INT so I can have wands. And if I need a weapon, I just enchant it with a stone of recharge so my low strength doesn't matter. If I were a character with high strength, I would focus on the INT so I could have ranged wands and powerful close up, and just forget about bows. And if I did want a bow, I would just enchant it with a stone of recharge and hope I find enough materials for arrows.

Enemies only activate their special moves if you are in the room or one square outside of the room. So, if a Pyrolisk burning you, get two squares out and it will stop. until it catches up with you. Shooting arrows or wand attacks into a room from this distance is an easy way to kill enemies at a distance without repercussions

Arrows and magic can be shot around certain corners.

Arrows, magic, use and throw moves are not affected by confusion, which is why a bow or wand can help you kill enemies and then recuperate after. Additionally, status affects such as counter damage from dolls and paralyze from eyes are not activated by these attacks.

The enemies that will kill you the most:
Any enemy that surprises you in a hallway.
Goblin Archers. You cannot nullify their arrow attack like fire/magic attacks, and they are much more likely to use their bows. I have died many a time shooting and arrow across the room at a sleeping enemy out of sight and getting killed when an arrow is shot back at me.
Vampires and Lamias that sleep, confuse or paralyze you.
Pyrolisks that burn you to death before you can get to them across the room.
Dragons with their ranged fire attack

Enemies to watch out for:
Golems: Have a wand of fire on hand to get around their high def and immunity to bad status effects
Any enemy with double move, critical hit, or double attack
Necromancers: They can summoner a surprising amount of zombies in a short period of time if you get bad luck.