When you spawn in go to the boxes to the right side of you and grab the crowbar
Head to the room through the mouse hole by the starting room and unlock the safe which contains the red key.
After obtaining the red key keep the crowbar in your inventory and unlock the basement door by the stairs (using the red key).
Skip going into the basement and instead go back and check the bedroom (door by the table) and the bathroom (connected to the bedroom) Inside look on the bed or dresser. There should be a green key (if not there then its either behind the chair upstairs or on the coffee table in the cage room). After you're done in the bedroom check the bathroom for the plank. If its not there then its upstairs (steps 6 and 7).
After doing that, go upstairs and use the crowbar on the green lock door and the door by the attic staircase. (now's the time to see if the green key is by the chair.)
Inside the room by the attic there's a lever (flick it to open a shortcut) The plank might also spawn there.
Use the green key on the green lock and enter. Inside is a generator and possibly the plank. Flicking the lever inside opens a shortcut.
Go upstairs into the attic and search the rooms. In the first room the key card could spawn there, along with this there is a level behind one of the pillars which opens a route that keys into the secret ending.
In the room by next to the first one can have the gas canister spawn in there. There's also a caged off door which is unlocked by following step 8.
Going down the staircase from the room in step 9 leads to a room which has the pliers and possibly the gas canister. Flicking the lever in this room unlocks a shortcut.
After knowing where the gas is head out and use the plank where its needed (through the door by the chair). Go back and either grab the gas canister or key card (if they spawned there).
Go back and grab the gas (if it spawned in the attic). Use it on the generators upstairs (in the green key room and attic room).
Go down to the basement either from the plank or basement door by the staircase. Use the gas at the generator that's in the basement. Use the crowbar on the exit door and blue key room (only if doing secret ending). You can also drop the gas and crowbar at this point.
Go back and grab the key card (either on the dining table, at the attic, or by the plank crossing area.
Use the key card at the exit door and you're free to escape!
Open the Attic by find either the Blue Square or Red Triangle.
Grab the Green Square, and go up to the Attic to unlock the Huge Lever
Use the Lever and jump down
Find the Yellow and Pink Key (If found earlier better)
Use the pink key and if CPU is there, grab it, if not, go to the room to the right of the electricity and grab it
Go into the Maicky Room and use the Yellow Key and CPU
Grab the Gray Key and use it in the Attic
Use the lever, then jump down and grab the pliers
Go back to the Attic and use the Pliers
Grab the Plug and put it into the Pink Room
Jump back down, and go to the room to the right of the electricity
Use the pliers in that room
Grab the Red Key and open the Red Safe
Use the Battery in the Maicky Room
Escape