The solution is based on the American version of the game, so it is possible to find differences in the Spanish version.
Part 1: Prologue
Slender: The Arrival begins in the parts of young Lauren who arrives at her friend Kate's house and finds the empty house and some bizarre and disturbing drawings. Armed with the trusty camera (and later with a very powerful torch), our heroine will decide to investigate on the spot, and be able to give an answer to the disappearance of her friend. In this first part, the chances of meeting Slender and consequently being killed by the elegant monster are reduced to the bone, so try to play this part in a relaxed way. From the car near the fallen tree, follow the low path of the road and enjoy the view, you will notice the radio tower, a place that will become an important reference point for the whole game; you will arrive at Kate's mansion at dusk and consequently the situation will certainly be scarier than during the day. Before entering the mansion, check around for the game's first collectible, the flyer of a missing child named Charlie Matheson Jr. The house will have been thrown upside down, objects scattered all over the place, and weird designs of trees on the walls. and of a man, at the base of the staircase there will be a backpack forgotten by someone. Begin your exploration of the mansion, and be sure to collect the letter number one to the left of the flight of stairs, go to the left of the main entrance into the room with the TV, you will find a note from Kates; enter the room with the piano, check the table to find a torch; head into the kitchen and check the fridge for a chalkboard and collectible, now turn to the table and pick up the funeral home flyer. Go down to the main room then on the left, you will find the bathroom and inside it a second letter, turn on the radio; here is Slender will appear outside the mansion, if the view starts to have disturbances turn immediately and move away from the window. Go back to the flight of stairs and go up to the second floor, try to memorize the floor plan of the house and the position of all the windows, they will be important later in the game, equip your, trusty flashlight and go left into the master bedroom, search a key on the bed, this will be the key to Kates' room across the hall. Exit the room, and open the door next to the window on the left, the walls will be filled with creepy drawings, one of them will represent the radio tower, check the bed for a note; now you will distinctly hear a scream in the dark, check out the window for a huge gate open to the dark forest. Exit the house, and on your way to the forest, stop at the small playground for the letter number three; now you just have to go through the wooden gate and immerse yourself in the darkness of the Slender forest.
Part 2: The eight pages
Following Kates' scream, Lauren decides to look for her friend, however something lurks in the darkness that surrounds her. You will start this part in a random area of the park, look for a small hut nearby, check the front and sides to find the fifth collectible, a canoe rental flyer, an inherent package, the park and another inherent, the rules behavioral to keep. Now you will have to dedicate yourself to the search of the eight pages, during this part, the entity known as Slenderman will begin to make its appearance, you will be warned of its presence nearby by a disturbance to the visual and particular noises of the audio of your camera, and of course you will see Slenderman himself. Your pursuer will be able to appear anywhere and teleport close to you at any time, looking directly in the face, you will make the visual and audio disturbances, more and more intense, if you spend too much time in this condition, from the body of the elegant monster will appear some tentacles, everything will become dark and it will be game over. It might be tempting to run, using the sprint button, to the pages once you have located, the stamina bar is on the screen, and once consumed you can only walk, so limit yourself only and exclusively to using the sprint skill to escape. from your pursuer if it is too close to you, or if so, get out early from any indoor location (such as the visitor center). Once you have found everything there is to find inside that place, you may find it too late that the way between you and the exit is blocked by Slender himself. The park and the arrangement of trees and structures will always be the same from game to game, however the position of the eight pages will always be different, due to its random nature, a real guide on how to find the pages is impossible to do, so the only advice I can give you while exploring the darkness of the park is to remain calm and visualize the map in your head in the most effective way possible; in the left part of the map there will be a basin of water, while in the right part there will be tall grass, in the central part a rocky quarry with three different exits. Try to take some reference points and always know how they are connected to each other, there will be ten of them present, many of them can appear anywhere on the map and they will be: the map of the park, the visitor center, a chemical toilet, a canoe, the water tower, an abandoned car, a tent, a covered warehouse, a lookout tower and an open warehouse. A good method, however, is to identify a precise place and try to follow a clockwise or counterclockwise path (at your preference), once you have completed a full circle, do a new one only trying to stay more internal than the first, if Slenderman should he appear, just back off and then retrace your steps once he leaves you alone.
Part 3: The abyss
Lauren will wake up near an abandoned mine, Kate has undoubtedly been in that place, the signs that indicate it are numerous, so you will have to try to reach the top of the mine by activating six generators in "random" positions within the area, give power to the mine. 'lift and go up; Obviously, Slenderman will be waiting for you here too, eager to make you the skin. This third part is simply the most difficult of the whole game, as in addition to the elegant man, a new enemy will be added, Proxy, the spirit of a not very friendly woman, who will kill you with two hits. The only way to escape will be to point the light beam of your flashlight in his face for a few seconds to stun him and run away. You will wake up, then, in a random position of the exterior of the abandoned mine, start your exploration, and once you come within sight of the entrance, look for a small building on the right, keep to the right and continue up to the rocky wall, look then to the left and you will notice a small path between two rocks, go that way to find the fourth letter; return to the mine entrance and stop by the building, check the barrels ahead for the fifth letter. Near the entrance to the actual mine, check for a notice board with the sixth letter, and a note from a worker, just before entering, approach the pipes, look for a hole nearby for a note from a man named Charles M. probably the same Charles from the missing child leaflet found in the prologue. Then enter the actual mine, enter the door on the right, collect the list of safety rules, go down the room, look for the seventh letter on the left, and finally an old newspaper at the back of the room. Go through the door until you are in the main area of the mine, here you will find four different corridors in the shape of a cross, two of them are still out of range, in the center there will be the console that controls the elevator, however at present the electric energy; nearby you will find a small portable generator that emits a red light, keep in mind the type of light it emits since you will have to find five more identical ones; it is at this very moment that Slender and Proxy will start hunting you down. Proxy has a different approach than Slenderman's, she will run directly towards you hitting you, most of the cases it will take two hits to send you to the other world, so try to stun her with the light beam of your flashlight, and as for the chapter previous, keep your stamina to escape from your pursuers. Finding the generators will be your priority, and since they too will be in "random" positions at each game try to memorize the structure of the mine since it will not change; to the left of the elevator there will be the corridor that connects two doors to the main area, here there is the real possibility of finding one of the generators behind a grate. A third door near the left apex in the corridor leads to three other rooms on the right, in one of these it is possible to find another generator; this corridor also leads to the highest part of the main area north of the elevator, with some metal containers, here you could find a generator on the far wall; from here you can climb a flight of stairs to reach the second floor, and a room containing three other rooms within which you can find another generator. Then jump on a metal container at the end of the hall to reach the first floor, on the other side of the huge area you will find a walkway that leads to the top floor of the right side of the mine, in the area to the right preceding the walkway there is the chance to find a new generator. The right side of the mine consists of a large room with the upper part facing the main floor, and also here the possibility of finding a generator on one of the two sides behind a grate; finally the part of the main hall to the right of the elevator has three rooms, and of course you could find a generator. A good strategy for exploring the mine is to start by going left through the lower door of the corridor, then exit and go to the right and continue up to the door on the left of the elevator, go down the hall checking every room, then turn left and enter the large closet; now explore the first floor, behind the stairs, then go up them and search the other rooms; then cross the walkway, check the upper floor, then go down and go to the right; end your exploration in the corridor to the right of the elevator by looking in the three rooms on the right. Once you have found all the generators and reactivated the elevator, use all your stamina to escape, however pay close attention, as Proxy could attack you even at this moment, so keep your flashlight in your hand even while running.
Part 4: The flashback
In this part of the game, Lauren will leave the mine by reaching the mountain to reach the radio tower, but will soon be distracted by a television inside a building, the broadcast emitted by the set, shows Kate on the night Slenderman has her. attacked, you will fully relive that night and, by controlling Kate, you will have to close all eight windows in the house before the dark (but elegant) man manages to take her. When you reach the top of the mine, walk through the hall to the exit, check the barrels on the right to find the eighth letter; then go outside and enjoy the view, check to the right of the fence for the ninth letter. Keep following the path on the ridge of the mountain and keep in sight of the radio tower, when the path divides, take the road that goes up to find the tenth letter attached to some wooden boards. Continue to a dark cave that leads to a small building, pick up the note in front of it then enter; collect the eleventh letter as well, now watch the television to start the flashback. As described above, the aim of this mission will be to close all eight windows of the house and the three main doors before Slenderman manages to break into the mansion; the problem is that he could enter before you have sealed everything, a message will inform you of this, at this point go to your room and if you have closed enough doors and windows, the mission will end. Start by closing the window in your room, then go to the corridor and close the window here too; now go down to the main room, check every window in every room; now go up the stairs and enter the master bedroom to close the windows; now go downstairs and close the main door as well. Go left into the dining room, close the two windows; go through the door into the kitchen, turn right into the garage and close the door; ignore the bathroom, go back to the kitchen and check the windows before closing the back door; if you still have enough time, check the last two rooms, the television room and the living room (the room with the piano) you will find four windows in each of them. At this point, Slenderman will appear in a random room of the mansion, go back to the dining room and go to your bedroom and hide in the clothes closet to finish this part of the game.
Part 5: The arrival
This is the last part of the game, your only goal is to run towards the radio tower, avoiding a really angry Slenderman and the forest fire, to discover the fate of your friend Kate. Exit the building and start the long climb of the mountain, when you take a bend to the right, check around you for a board with the letter number twelve, keep following the path that climbs until you reach a new dark cave. Once inside, look at the signs on the wall, right in front of you you will find the last letter, the number thirteen, and nearby following the path on the right you can collect the last collectible in the form of a note; the marks on the wall say it will end up in the fire, and indeed it will. Exit the cave, only a fiery forest separates you from the radio tower and, of course, Mr. Slenderman who will try to hit you with his horrible tentacles on this tour. Watch out for flames and falling trees, continue to keep the radio tower in line of sight, pay attention to the signs of two blackened trees falling along your path, you can just stay in the area where they fell while continuing to avoid the flames. If Slenderman should show up, try to escape to the other side without getting lost, trying to remind you of the direction you were taking before the appearance of the man in black. Finally you will reach the radio tower, the door will close behind you; there will be only a few rooms inside the tower, look for the pair of keys in the room on the right, then open the closed door and start running without stopping; your flashlight will run out of batteries but you keep running whatever appears in front of you or around you. Once you turn the last corner you will find out what happened to Kate; activate the camera to hear each of the last moments of the girl's life. When the video ends, the lights at the end of the room will go out and something inhuman will approach you. Congratulations, you've just finished the game, and if you've played on the higher difficulty, enjoy the full ending too!