This has been posted in response to the community. Alot of people managed the puzzles fine, a few struggled on a number of them. So if you're stuck, feel free to wallow in the knowledge of our walk-through below!
--Obvious Spoilers Ahead!--
Mansion - West Wing
At the start of the game, your first goal is to gain access to the kitchen and investigate. To get there, you’ll have to explore a few maps starting with the west wing. There is a locked door straight away to your right. This requires a key found in a later map, it will lead you to a tool shed which you need to access to breakdown the upstairs barricade. Ignore this door for now.
First off you’ll need to find yourself a key for the locked door at the top of the stairs. The key is located in the top floor of the dining hall, amongst the junk in the barricade. Once you've found it, head to the locked door at the top of the stairs. Unlock the door and proceed.
Mansion - Upper Courtyard
Once you enter the Courtyard for the first time continue along the balcony to the east wing.
Mansion - East Wing
Once inside the east wing, you’ll need to head right and down the corridor until you reach the stairs. Descend the staircase and enter the room at the bottom and pick up the key placed on top of the drawer. Head back out into the corridor and take the door at the end to your right. This will take you back into the lower courtyard.
Mansion - Lower Courtyard
Once in the lower section of the courtyard, you will need to follow the railed path until you reach a cross section. Take the steps down to your left and turn left again at the bottom. Enter the tool shed and obtain the crowbar. Return back up the steps and turn left back towards west wing. The key you acquired in east wing will unlock this door. Continue through the door.
Mansion - Returning to West Wing
Now that you have a trusty crowbar, head up the stairs to your right and take a left at the top. Enter the top floor dining hall once again and use your crowbar on the barricade. After removing the blockade, enter the hall and follow it until you reach more stairs that descend round a 90 degree angle. When you have reached the bottom of the stairs, the kitchen is to your left. Enter it and in the back storeroom you’ll find a hole in the floor which will lead you to the next map - The Sewers.
Now you’re in the sewers. After the cutscene ends, move onwards until you hit the water-filled area. Once you’re in the water, you need to advance until you reach a ladder. Climb the ladder, find a few supplies including an oil barrel and take the second ladder down into, yep you guessed it - more water.
Once you explore this next water section, you will find a door at the far end that is inaccessible due to collapsed stairs. To open this you’ll have to complete a puzzle which will allow you to walk along the pipes above you.
To begin with, pull the lever near the foot of the collapsed staircase. This will open a gate that you may have spotted earlier. Backtrack towards the source of the gate sound and climb the ladder inside. At the top of the ladder, you will find a room and an over-looking balcony. The balcony will contain eight levers, four of these need to be lowered and four need to remain up. There is no set solution to this as they are all randomly generated so just pull any combination of four levers until you succeed.
When you successfully complete the lever puzzle, the camera will show you where to climb onto the pipes. Jump up and follow the pipe round until you eventually stand above the inaccessible doorway. Drop down and enter the next section.
This map is fairly simple in terms of objectives. Simply keep walking down the sewer until you find a doorway that will lead you to the next map - Portal
In this map, you’ll need to access the portal. To do so, find a note containing the ritual rites to the portal. The note is on the throne surrounded by the seven scrolls. After obtaining the note, walk to the back of the room by the large door. If you have this note, walking up to the door will start the ritual and will eventually load into the following map - Hub.
Congratulations on reaching the central hub! This is really the strong part of the mod.
First things first, the Horsemen’s realm is divided into five areas. They are War, Death, Famine, Pestilence and the final chamber. You will be able to enter War, Famine or Pestilence for now. Death will open up once you have finished and obtained all other orbs and the final chamber will open once all four orbs have been collected.
If you try to access a quarter now, Alistair will claim he needs to rest before continuing. A suitable and hidden place is located under one of the staircases (The left one as you enter through the portal). Walk into this area to rest and following this, you will awake fully healed and fully sane!
Now it’s up to you - pick a quarter!
When you enter this quarter, you’ll find a long corridor filled with poisonous gas. If you attempt to enter the gas clouds, they will harm you until you eventually suffocate or leave the gas. Behind these clouds lies the Orb. However, you will not be able to stroll through the gas just yet without dying.
So your first task is to formulate an antidote. The first doorway to your right as you enter, will take you to the laboratory and storage. As you enter this door, you will be met with two paths and one closed path. The path in front of you contains the alchemy lab. Here you will brew your immunity potion. Before you can do that, you need four components. One is found within the lab itself and the remaining three are in storage. Take the first door on your left and eventually it will lead to a room full of shelves and alchemy ingredients. All three components are located here, take some time to find them before climbing the ladder opposite to the way you came in.
The ladder you have just climbed will take you back to the lab, continue on until you reach it again.
Once at the lab, use all four components on the lab apparatus. When all four are placed, the potion will spawn at the end of the apparatus. Picking up the potion will make Alistair drink it. After Alistair has passed out from taking the antidote, you will return conscious and you can now enter the gas clouds.
The potion is only semi-effective however, so you will still take damage and die if you delve too far into the clouds. It will still allow you to get further in this time. On the opposite side of the gas corridor to the lab, is another door. Take a laudanum if you need to and run for that door.
Once in the second area, you will be met with a staircase which ascends to the machine room. In here you will need to turn on the ventilation machine which will extract all the gas from the room below. You are now safe to traverse through the remaining corridor below. Go back down the stairs and collect your reward - The Orb of Pestilence!
Return to the Hub and chose your next Quarter.
Upon entering Famine, you will be met with two routes. Both routes will just take you around a central column and met each other again, so it is irrelevant which one you take. After this, you will be met with a portcullis. Using the valve next to it, open the cullis and enter the next room. The cullis will close behind you.
Once in this room, you will be faced with a spawning mob - The infamous ‘Loopy Brute’. He will smash the door down at the far end so find a hiding spot! He will then proceed down the staircase and will patrol in a circle around the support pillars in the middle of the room. He will walk round anti-clockwise, so you need to time your escape and when he passes you at the right time, bolt for the door he smashed down - this is your only path out of this room.
When you have reached the smashed doorway, assuming Loopy has caught onto your foolproof plan, continue down the corridor. You will come to a ‘heavy gate’, a locked door and a door with a small room behind it. In the small room you will find a valve which opens the heavy gate. This is again timed to close so you’ll need to open it and run as fast as you can to get inside the cullis. If you happened to have a falling out with Loopy, use a laudanum to heal yourself, it will give you full run speed.
Once inside, walk on into Famine 02!
This level is fairly small. In it there is a large open room with five portcullis’. Behind one is the Orb you seek and behind the other four are traps doors which require various offerings of food. Besides this, there is a small room serving as a food store. In here you will find the bag of apples, bag of potatoes and loaf of bread that you need for the puzzle. Don’t worry if you make a mistake, the items will respawn. The last donation (meat) has a rotting pig corpse outside it’s door, use this to complete your meat donation.
Once completing the donations, the Orb chamber will open. Go in and collect your prize - The Orb of Famine! In here there is also a key on the floor which you will need to leave the quarter.
The key opens the locked door at the top of the stairs by the storeroom. Use the key and return to Famine 01.
Returning to Famine 01
Once back in Famine 01, you need to find the crank on the first room floor, then use the hatch to drop down into the dreaded Loopy room!
Whilst you have been donating to Famine, Loopy has been busy looping round and round. You will need to time your escape again to return safely. When you try to use the cullis at the end of Loopy’s room, the valve will snap off. Use your wooden crank to open the gate and run out before you get spotted!
Congratulations on completing Famine!
Welcome to War! It’s a place with some nice things to see so let’s get started! In the first room you will see an Orb mold. This will be vital later so remember about this, for now move on. In the next room is the great forge. This is also vital later but again for now, keep advancing through the quarter.
After continuing down a staircase and through the armory, you will find a T-junction. The left route takes you into a room you’ll need to access. The route right takes you to the War Room! But before you can enter, you’ll need to buy your way in with a weight of Thalers. You need 250 Thalers in total so if you see any, grab them!
Enter the left route. In here, you will encounter an earth tremor, after which you will be left in darkness. On a crate in the corner you will find a key that opens a chest in the center of the room. Open it and find within a wooden lever. This lever needs to be placed into a lever base which sits on one of the two stone pillars in the room. Put the lever in and use it. This will open a secret entrance within the wall ahead of you. Enter here and find a hidden lever behind the first doorway. This opens a second wall which you can enter and will take you into some water...Oh yay.
Continue through until you reach the ‘Impossible Maze’. Here you will need to move through the maze in the correct sequence to succeed. Step into the first square of the maze and follow the following order: forward, right, right, left (through the portal) forward (into the maze again), right, forward, forward, left, left, right, left, left, right (And out of the maze again).
Continue until you reach a ‘Mechanical Lubricant’ and a lever which will open your exit. You are now back in the room where you experienced the earth tremor. Use the lubricant on the seized lever and use the cullis to exit this room.
By this stage you should have found enough Thalers to open the War Room. If not, backtrack until you find enough coins. Once you have enough, click on the donation basket outside the War Room and the door will open. In here you need to obtain five objects. Four of them are broken pieces of the war orb and the fifth is an empty container.
Once you have all those items, return to the great forge from the beginning. Here you need to use an orb piece to melt the orb down. Once you have the liquid of of War, use it on the orb mold at the very start of the map. Collect the Orb of War.
Return to the Hub!
Once you have all the other Orbs, Death Quarter can be found accessible after the broken cullis has been smashed open. Enter Death!...Trust me, it’s fine.
Walk on until you reach two doors and a staircase. Go up the stairs to straight on at the top. You will reach a room with hanging chains and a door on one side. Enter the door and find a lever inside. This will engage a cullis which you need to use now. Leave the room again but this time go down the righthand corridor. When you can go right again to a cullis, open it and enter.
You will now be shut inside, keep going right and through the door. Go through another door and into a room with an illuminated, raised alcove. At the end of this room is a flight of stairs with a locked door at the end. To get through here, you need to grab the large rock at the top of the stairs, and push it down the stairs. The door will smash open. Continue into Death 02!
Walk on, you will find a room with a corpse pit in the center and you will be able to walk around the outside but not get to one of the sides. To proceed, you need to find an opening into the center and you will be able to jump onto some suspended beams. Travers (carefully) across them until you reach the other side. Continue on until you eventually find a load door for Death 03.
In this room, you will need to sacrifice a life to access the Orb chamber. To start with, descend the stairs to the point where they bend left. Now look to your right and find a chain which you can use to climb down. Lower yourself onto a hanging beam below and climb up the other side. Jump off the chain onto some beams and do a run-and-jump onto another chain at the end of the beams you’re standing on. Climb up and jump off onto the ramparts. Use the levers to lower all three bridges and walk into the small chamber with a chained man inside.
Artur, the guy from the notes, has been captured and imprisoned. He will be your sacrifice (how helpful! Thanks Artur!). You need to burn him alive. To do so, run back across the bridges and grave yourself a barrel of oil. Bring it back to Artur and place it on the firewood (it should snap in place). Once it is correctly placed, you can light the fire and sacrifice him. After a small cutscene, you will now have access to the Death Chamber!
When you enter, you will find a circular room. On the opposite side is where the orb is located so travel around the room (either way) and retrieve it.
You have completed Death! Return back to the Hub.
Hub - final section
Now that you have all four Orbs, you can enter that doorway down the bottom of the stairs in the hub room. Walk down the stairs and the doorway will open automatically. Enter the room ahead of you and continue onwards to find a lever that opens a cullis. Walk through the cullis and it will lower behind you. Notice the souls and barrier to the sides of where you stand, they will damage you should you go to close so keep your distance.
Open the next cullis using the lever besides you and do this for the next two cullis as well. Once you have reached the final chamber, you will see ahead of you four pedestals. Each pedestal has its own Orb assigned to it, the objects surrounding them will show you which is which. Be warned however, when you place your first Orb down, Katherine will attempt to kill you! You have twenty seconds to complete your task before you will die from the damage, so be quick in placing the orbs!
A cutscene will play followed by the end credits. Congratulations on completing the Four Horsemen!