This looks interesting, love the backdrop. The transition in the soundtrack is great. I'd almost got used to the rain, so when the kids start talking about the hand the new music does make it feel more important/mysterious. I'm enjoying it so far, especially the element of discovering new locations, which promises a lot of exploring in my future.
*Very* minor things, just in case you plan to polish the translation and fix typos:
Page 114: I think "trees wall" can just be "tree wall," and "descend" should be "descends."
On page 142, "Suddenly" should have a comma after it. Better yet, just drop the suddenly. It's one of those weird things with the psychology of reading that the time it takes to read the word 'suddenly' makes the events following less sudden and surprising than just mentioning them outright.
Also, I don't really get using << and >> instead of quotes for dialogue - especially when you use scare quotes just a paragraph later. Is it because it is over the loudspeaker? I'm not sure that would mean quotes aren't used. Also, the period should go inside the endquote or >> or whatever you use.
Since their are two kids on the sign, "expressions look" would fit better than "expression looks."
Page 12, "jeans jacket" should be "jean jacket."
Page 118: The sentence about the canopy and reception is a little ambiguous, as it reads like the canopy itself is made of wood vs. the reception building. If you are using the oxford comma, there should be a comma after maps.
97: A semicolon would make more sense than a colon in the sentence about the kids talking to each other. Odd use of <<>> again. One of the dialogue lines ends with "its" - it isn't clear whether that was supposed to be "it," as if they are speaking of a mysterious object, or "its" and they just stopped mid-sentence (in which case, a dash or ellipses would clue us in.)
81: comma after "ends the other one," before looking. Comma after again in the last dialogue line. The colon seems odd here, but I'm not sure a semi-colon is quite right either. Maybe just use a period? "Their" story would be more clear than "this story." I'm not sure the page tag works here - telling me the "tension mounts" is actually less tense than just letting the tension naturally mount ;)
50: Comma after suddenly, or, as mentioned before, just get rid of the word "suddenly."
This line is a little fuzzy: " On the stage one of the guys that accompany you holds a microphone in his hand. " Perhaps "On the stage, one of the guys that had accompanied the kids earlier holds a microphone in his hand."
Typo - "fot that person" instead of "for." There should be a comma after "lake" in Mike's dialogue. Another typo, "fell" instead of "feel."
The page transition is also odd here. "Something at 147 catches your attention..." It might be better to mention something catching your attention, or that a sound or noise happens, etc. instead of putting it in the turn page blurb. Or just move to 147 and don't spoil the surprise that something odd will happen.
147: There's a paragraph here that reads strangely:
"In that exact moment a lightning illuminates the outside square. Close to a building, a motionless figure despite the rumble of the thunder, is watching you.
In a second the square turns dark again and in place of the appearance only a bright red dot remains, but one thing you know for sure.
That figure was lacking of a hand."
Perhaps try: "In that moment, a flash of lightning illuminates the outside square. Close to one of the buildings, a motionless figure is watching you, seemingly unphased by the rumble of thunder. The square turns dark again, and only a bright red dot remains of the being's appearance. But even though the glimpse was brief, one thing you know for sure: the figure was missing a hand."
Typo in the transition, "thee" instead of "the."
180: typo, "feets" instead of "feet." Should be a comma after small, and probably after sleep as well. There's an extra word "was" after stop. "His brother" should be "their brother." Should be a comma after "day" in the last sentence.
The transition here is also a bit meta. "If you have the green piggy, go too..." Ideally, the game would know or there would be some way to use the item without requiring the player to be honest here or taking them out of the story. That might not be possible, but if it is, try to do it in a way that isn't so obvious.
37: There should be a comma after "Luckily." "Slips" should be "slip." The transition is very meta again, asking me what I have in my inventory.
75: Comma after "instinctively."
179: It should be a semi-colon here instead of a colon. Comma after second. Typo: " auditorum" should be "auditorium," and there should be a comma after. Another colon that should be a semi-colon.
"You slowly go" should be "You are slowly heading back" based on the rest of the sentence. "Manage" might be more clear as "can turn."
139: Comma after suddenly, or drop the term. Also, the soundtrack continues here with rain and even ramps up with some storm and bird noises, which is at odds with "the rain stops..."
Complicated sentence fragment: " You realize being under an umbrella only when an annoyed voice at your back reproaches you"
130: "I Got You Babe" should be in quotes. "Dream where " is a little unclear, so "dream, one where" would transition the topic better. " tell them" doesn't follow with what you told them - "of the night's events" or "of the mysterious figure" or "of the hand" would be more clear. Needs a comma after everywhere and singing. "That kind of mysteries" should either be that/mystery or those/mysteries. "Out" could more clearly be "Once out." A comma should follow hall. The colon should probably be a dash or a period.
166: "Private camping needs" should be "private campsite need." "Applauses" should just be applause.
Anyway, I look forward to continuing this one.