Straight forward walkthrough, if you talk with someone exhaust all options.

START:
Go to Cathedral.

CATHEDRAL OUTSIDE:
Open Door to the Crypt.

CRYPT:
Talk to ??? (Brother Thiago).
Pick up Board game (Get Rule book).
Exit.

CATHEDRAL OUTSIDE:
Go to the left or right.
Go to the Entrance (of the church).

CHURCH ENTRANCE:
Pick up Alms bag.
Go to Right hallway.

CHURCH RIGHT HALLWAY:
Talk to Mrs. Beatrice.
Talk to Priest 2x (you notice the key, but can't get it).
Go to Altar (to the left).

ALTAR:
Open Little door (Get FunBoy)
Open Door.
Enter Door.

CHURCH OFFICE:
Walk on Loose Tile, we will get back to that later.
Exit.
Walk left to the left screen of the altar.

CONFESSION BOOTH:
Open Confessional booth.
Achievement #01: Secret of confession
Leave the church.
Walk to the left to the bar.

STATUS QUO BAR:
Talk to Status Quo's security (Get Stamp on hand).
Open Status Quo door.
Go to Bathrooms.

BATHROOMS:
Talk to Maria.
Look at Long Live Punk Rock.
Achievement #02: Long Live Punk Rock!
Exit.

STREET:
Talk to Data.
Say "Come on, we must look somewhere else!" (this will bring up the map).

CENTRAL SQUARE:
Use Alms bag with Pile of sand.
Talk to Kid 3x.
Pick up Wodden screwdriver.

CHURCH OFFICE:
Use Bag of sand with Loose Tile.
Pick up Insult key ring.
Use the Insult key ring with all the current people you can find (except the kid in the Central Square).
Achievement #03: There's a new joker in town

POLICE STATION OUTSIDE:
Talk to Fortune-teller.
Look at Portrait.
Open Police station door.

POLICE STATION INSIDE:
Talk to Chief of Police.
Look at Door 3x.
Achievement #04: Guuaarrdd!!!
Pick up Fortune Crystal Ball.

POLICE STATION OUTSIDE:
Give Crystal Ball to Fortune-teller.
Talk to Fortune-teller.
Ask about the winning lottery numbers.
-The last shall be first.
-The twins are divided, the one on the right will go last.
-The one on the left remain in its place.
-The first will be third.

HOSPITAL OUTSIDE:
Go to Access to Parking Lot.

PARKING LOT:
Talk to Thief.

Exit.
Open Main door.

HOSPITAL RECEPTION:
Talk to Rudy.
Achievement #05: Scary goat
Open door.

HOSPITAL CORRIDOR:
Open first door on the left.
Pick up Fabric scissors.
Exit.
Go to corridor on the right.

CENTRAL SQUARE:
Use Insult key ring with Kid (Get Firecrackers).

PARKING LOT:
Give Firecrackers to Thief (Get Coffee Token).
Achievement #06: I failed the CBC
Exit.

PARKING LOT:
Achievement #07: Accesory to a felony
Pick up Dielectric Gloves.

HOSPITAL RECEPTION:
Go to the first door.

REPAIR ROOM:
Use Wodden Screwdriver with Plug.
Achievement #08: Amateur electrician
Use Dielectric gloves with Electrical board.
Look at Electrical board.
Touch the blue wire on the left and right of GENERAL.
Connect the two blue wires together.
The Reception switch should be on the left.
The E&S switch should be on the right.
Flip General switch.
Exit.
Go to door.
Enter Second door.

STORE ROOM:
Pick up Sheets.
Use Fabric Scissor with White sheets.
Look at Rule book in inventory, combined with the tips from the fortune-teller you get the combination.
Look at Mysterious box.
Touch Padlock (9242).
Pick up Token.

HOSPITAL CORRIDOR:
Use Coffee Token 2x with Coffee Machine.
Use Coffee Machine.
Pick 3. Energy shot (Get 2 batteries).
Use Batteries with Funboy without batteries.

CHURCH ENTRANCE:
Use Bell.
Talk to Sister Anya (ask about trophy).
Give Funboy to Sister Anya.

CONFESSION BOOTH:
Open Confessional Door.
Pick up Journalist-type recorder.
Open Tape recorder.
Walk outside.

Give Cassette with prayers to Data.
Use Inverted Cassette with Tape recorder.

HOSPITAL RECEPTION:
Use Tape recorder with IV pole.
Use Altered ghost sheets with Rudy.

POLICE STATION:
Talk to Rudy.
Achievement #09: You'll be here forever.

STATUS QUO BAR:
Talk to Maria.

CHURCH RIGHT HALLWAY:
Give Music score to Mrs. Beatrice.

CHURCH OFFICE:
Pick up Key.

CHURCH RIGHT HALLWAY:
Use Stairway key with Padlocked door.
Go to Stairway door.
Go Staircase up.
Look at "The Crufifix" wine.
Achievement #10: Wordplay
Pick up "The Crucifix" wine.

CRYPT:
Give Crucifix wine to Brother Thiago.
Go to Hatch.
Go to Corridor.

PRISON:
Pick up "Food" Plate.
Pick up Green sock.
Push Bed.
Get Spanish Card.
Talk to ???
Talk about the hat and he will drop it on the floor.
Pick up Hat.
Use Hat with Skeleton.
Use Green sock with Rat.
Push Loose Brick.
Use Melted spoon with Plastic cover.
Give Spanish card to Number 5.
Use Rat in a sock with Wires.
Go to Exit.
Achievement #11: Free Splinter.

HALL:
Walk to the right most door and enter it.
Use "Food" plate with Sign.
Achievement #12: Bad bad Greene!

GUARD'S OFFICE:
You will automatically get your stuff back.
Look at Book.
Achievement #13: Horror novels fan.
Use Schedule Board, notice the location of the blue notes.
Exit.

HALL:
Use Levers.
Answer:Up, Middle, Up, Down, Middle.
Press Red button.
Exit.
Walk: Up, right, up, left, left, up.

Once outside the maze, walk to the right.
Go to elevator.

CENTRAL SQUARE (Back as Claire):
Look at Slide.
Achievement #14: Nostalgia trip
Use Bike.

NEIGHBOURHOOD:
Enter Fonda-Soft store.

FONDA-SOFT STORE:
Talk to Ariel.
Pick up all games to hear all Ariel's jokes.
Achievement #15: Resilience to bad jokes
Exit.

NEIGHBOURHOOD:
Talk to Floppy Disks child (Need Basketball).
Walk left.
Talk to Kids (Need TrackBall).

DOWNTOWN:
Walk to the right.
Talk to David.
Pick up the Trash can (Get Sturdy paper).

PLAZA BITTO:
Talk to ??? (Need Invitation and Aluminium).
Pick up Empty glass.
Exit.

DOWNTOWN:
Talk to Santa's helper.
Achievement #16: Child labor
Talk to Santa Claus.
Go to Pirulin Pirulero door.

PIRULIN PIRULERO:
Get Extendable hand.

CATHEDRAL OUTSIDE:
Walk to the bar.
Pick up Carpenter's pliers.

CATHEDRAL STAIRCASE:
Use Empty glass with Water drop.
Walk up the staircase.
Talk to Very, very scared man (Need Aluminium hat).

CENTRAL SQUARE:
Talk to Diego (Get Tape backup).

HOSPITAL:
Talk to all 3 War veterans (Need White cane, Scarf and Collector's vest).
Use Carpenter's pliers with Screw.
Use Flat screw with Extendable hand.

MILITARY HIGH SCHOOL:
Use Repaired extendable hand with Basketball.

DOWNTOWN:
Give Tape backup to David (Get Seal remover).
Achievement #17: Friends will be friends.
Use Seal remover with Hand with stamp in inventory.

PLAZE BITTO:
Give Rest of stamp to ???.
Give Sturdy paper to ???.

CATHEDRAL STAIRCASE:
Give Tin-foiled hat to Very, very scared man (Get White cane).

NEIGHBOURHOOD:
Give Basketball to Floppy disks child.

FONDA-SOFT STORE:
Pick up and try to buy any random game.
Pick up Trackball.

NEIGHBOURHOOD:
Give TrackBall to Kids.

DOWNTOWN:
Give Police Quest III codes to Santa Claus (Get scarf).

PIRULIN PIRULERO:
Look at Mogwai.
Achievement #18: Retro movie freak!
Use Glass with water with Mogwai.
Go back in.
Pick up Movie Vest.

HOSPITAL:
Give the Cane to the left War veteran (Get Military hat).
Give the Scarf to the middle War veteran (Get Military pants).
Give the Vest to the right War veteran (Get Military jacket).

CENTRAL SQUARE:
Talk to Diego.
Give him the Military items.
Achievement #19: Military outfit

THE END (See you in the third and last part).

Achievement #20: Postcredit nerd scene