Typos and stuff:
Initial tutorial bit: passed > passes (see below for a more comprehensive rewrite of the entire intro)
Random NPC chatter about girl with axe: an > the
Random NPC chatter about building formations: formation > formations
Random NPC chatter about Lord Zetta having woken up: worken > woken
Random NPC chatter about having to fight every day: everyday > every day
Random NPC chatter about checking equipment: millennia > millennium (entire message is a bit quirky, but in a charming way - this fixes the only real issue I had with it)
Random NPC chatter about changing a lot: For thousand years... > For a thousand years...
Random NPC chatter about returning Zetta to old body: I wonder if how can we > I wonder if we can
Random NPC chatter about momentary peace: Lacks a period at the end.
Random NPC chatter about Zetta disappearing: What > what
Random NPC chatter about the Yoshitsuna-is-coming dream: It > Is
Random NPC chatter about dying to a weak attack when critical: your > you're (you + are, we don't need the possessive form!)
Random NPC chatter about what Lady Petta thinks about you: if what does > what
Random NPC chatter about fighting Great/Ultra Overlords: a Ultra Overlord > an Ultra Overlord
Conversation after first battle, after Petta warps out: there's, > there's
Stage 1-6: Out of bounds, rename to "The Demon's Army Attacks!"?
Stage 2-3: Out of bounds, rename to "Underwater Chem Lab"?
Stage 2-4: Out of bounds, rename to "Gourmet Club"? (couldn't think of anything better :E)
Stage 3-1: Out of bounds, rename to "Devil's Sky Land"?
Stage 4-1: Out of bounds, rename to "Overlord's Castle"?
Suggestions and oddities:
Tutorial: *insert 5 in-game pages/dialogs of text here*
The second page is a bit awkwardly worded, and I haven't really been able to figure out the third and fourth pages yet. I think a full-on rewrite may not necessarily be a bad thing here, especially since some of this stuff doesn't really tie in with the story either. I'll try my hand at something later.
NPC chatter: "That girl with an axe... It's like she's very attractive, isn't she?"
The "It's like" bit is redundant and makes the sentence awkward, cutting off that part sets things right.
NPC chatter: "First of all, you should begin on observing your unit's levels."
A bit vague (and not entirely correct either), maybe replace with "Keep a close eye on your enemy's levels. If your individual characters are too weak to kill an enemy, have them gang up!"? Two flies, one stone.
NPC chatter: "I can't really understand it very well but, when will we get out salary? Although, I didn't really receive anything yet..."
Can be condensed into something like "I don't really understand these things very well, but when are we getting our salary?", which would also fix the grammar.
NPC chatter: "To add more character units, approach an item and confine em'. Go, and multiply!"
Small fix: "To add more characters, approach an item and confine 'em! Go on and multiply!"
NPC chatter: "Summon more buildings to make it lively! To congratulate Lord Zetta's comback."
Small fix: "Summon more buildings to make things more lively! Why? To celebrate Lord Zetta's comeback, of course." (could do without the ", of course." bit, but I felt it would add some more personality)
NPC chatter: "For the first time in a 1000 years, doesn't he forget a lot of things? The question is, is it safe?"
I think I get what the idea was here, but it's grammatically incorrect. Potential replacement: "I know Zetta has been asleep for a thousand years, but... isn't he being a bit too forgetful?"
NPC chatter: "Then again, this is the beginning of an interesting battle. I can't wait to put my skill's into action."
Small fix: "This is the beginning of an interesting battle. I can't wait to put my skills into action."
NPC chatter: "Moreover, if you fight Lord Zetta alone no good will come out of it."
Small fix: "If you fight Lord Zetta alone, no good will come out of it." (Moreover would suggest continuing an existing conversation, not starting a new one)
NPC chatter: "I can't change my job unless I train harder!"
Grammatically correct, but this also shows up on characters that DO have enough mana to reincarnate. I'm not really sure about a good fix, though something like this could work: "You'll need mana to make wishes in the Tome. If somebody is lacking mana, have that somebody kill some more enemies."
NPC chatter: "You can have upto 1200 items in the inventory. Use it well."
Small fix: "You can have up to 1200 items in your inventory. Use them well!"
NPC chatter: "Where did Lord Pram go? As the 0013th Fan Club member this is going" *lags for a bit, next line* "inventory. Use it well."
Broken, so I can't tell what is supposed to happen. Lord Pram should probably become Lady Pram, though (and 0013th > 13th).
NPC chatter: "You can't really expect to see all of the Overlord's to appear. Is this some sort of conspiracy?"
Not sure what this one is supposed to be about. Potential replacement: "I want to see ALL of the Overlords, but I don't think it'll ever happen." (a bit weird, but it could work)
NPC chatter: "If your feeling weak about your units, go to the Training Dungeon"
Small fix: "If you feel your units aren't up to snuff, head on over to the Training Dungeon."
NPC chatter: "Which reminds me, isn't it that Lord Salome is the former apprentice of Lord Zetta? What did he teached her?"
Small fix: "Wasn't Lady Salome a former apprentice of Lord Zetta? What did he teach her?"
NPC chatter: "Hmm? Did that girl with a blue hair just walked by? I'm not familiar with that one, who is she?"
Small fix: "Hmm? Did a strange blue-haired girl just walk by? I haven't seen her around before, who is she?"