Hey, welcome to an overly detailed guide for completely unknown (and not a very good) game. I happened to need the exact room count of the game for a crappy joke in a crappy YouTube video, so naturally, I went ahead and mapped the entire thing. Thought that in case anyone would like to play this game, for some inexplicable reason, might as well leave this here so that your experience can be a better one than mine was - although I must confess, trying to map the whole thing was probably more fun than the game itself (and trying to map the whole thing wasn't very fun to begin with).

Countless Rooms of Death is a fairly simple looking horror game with abhorrent puzzles - it, however, is quite cheap so you can send many, many copies to anyone you hate. The game mostly relies on its atmosphere - a dark maze of concrete rooms with obscure medical equipment, blood stains here and there. While it's mostly the atmosphere and not knowing what to anticipate, there are a couple really timid "jumpscares" in the game - if that concerns you.

The controls are pretty standard but since they are outlined nowhere in the game, have them below for clarity sake.

W, S, A, D - movement
Mouse - camera control
E - interact, use

1.1 The start room.
1.2 The exit room.
1.3 Key one: play a game of three cups (boxes?), one ball. It is very easy BUT if you do not identify the ball location correctly you will be killed and have to start the area over.
1.4 Key two: set the.. "puzzle" wheel? to the correct astrological signs. These are, in order, going from top to bottom: Cancer, Libra, Sagittarius, Aquarius.
1.5 A clue room for the key at 1.4 - I have never seen a different combination than the one above on anyone's playthrough but in case it somehow doesn't work, check here.
1.6 A "story" related choice, the only one in the game. Don't think too deep into it though, whichever you pick does not seem to affect literally anything.
1.7 "Maze" room with a 7x7 tile grid in it. If you step on the wrong tile, you will be killed and have to start the area over (resetting keys you could have gotten at 1.3 for instance). The safe path is shown next to every entrance to this room - an example of one of them is pictured below.


(in-game hint for traversing the 1.7 maze room)


(in-game hint for the 1.4 "puzzle" in room 1.5)

2.1 The start room.
2.2 The exit room.
2.3 A steam-filled room which if you enter prior to "solving" the "puzzle", you will be killed and have to start the area over. See 2.4:
2.4 A room with series of pipes with valves on them - you have to turn the correct ones, which are, going from left to right, the second, third, fifth and seventh.


(the pipes which need to be activated in room 2.4)

3.1 The start room.
3.2 The exit room.
3.3 Key one: you will find tiles with crosses and circles in the room's middle - you need to clear them all out in order to receive a key. The catch is, if you activate a wrong tile, you will be killed and have to start the area over. This is possibly the most infuriating "puzzle" in the game, because other than trial and error I couldn't find any logic behind the order of clearing the tiles out. There's only a couple of "problematic" tiles, so there is many possible solutions, but I'll append the one I used below regardless.
3.4 Key two: There is 3 number slots on the wall, which you need to set to "666" (yeah, right). The hint for this is a red six written on all three of the patient files found in area 3.


(one of the possible solutions for room 3.3)

4.1 The start room.
4.2 The exit room.
4.3 A "puzzle" room allowing you to clear 4.4 and progress further. Turning off (red colour) the 6 middle machines on the right side of the room.
4.4 A dangerous room filled with deadly... light? You can pass through only after solving 4.3 - otherwise you will be killed and have to start the area over.


(a solution for room 4.3 - perhaps one of the possible ones?)

5.1 The start room.
5.2 The exit room.
5.3 Key one: using the buttons, rotate the three circular painting pieces to line up properly with the spectacurlar work of art.
5.4 Key two: use the buttons on the sides of the room to first fully light all the lights, then turn them all off again to receive the key.


(the correct setting of the painting in room 5.3)

6.1 The start room.
6.2 The exit room.
6.3 A "puzzle" room, requiring you to activate (use) the separate "pieces" of the "D" letter near the window in the wall in a set order. There is a clue on how to do this on a wall nearby but I am appending the piece order anyhow.


(the order the small white D fields need to be activated in)

After this is done, nothing visibly happens immidiately - however, when you go back, the dead end wall separating room 6.2 will be gone.

Do note that due to a bug in the game at the time of writing, the wall does not collide with the player, meaning the puzzle can be skipped and you can walk through this wall prior to solving the 6.3 "puzzle".

7.1 The start room.
7.2 The exit room.
7.3 Key one: there is are incomplete letters on the wall and you have to pick the correct letters using the nearby buttons. The objective is to have the sentence say "That was MY fault".
7.4 Key two: choose the correct "path" for the little white dot to go through from one side to the other and back. You can preview the three choices - the correct answer is pressing the third button at the buttons labeled "final choice". If you press the wrong button, you will be killed and have to start the area over.

8.1 The start room.
8.2 The final room. It contains gigantic books in the first and second "floors". You need to activate the correct ones in relation to the patient files, but because you are not required to do so in a set order, the books don't reset if you pick the wrong one and wrongly picked books are automatically rejected, simply go left to right on both floors and activate all of them. Doing so will end the game.
8.3 Use the buttons to shift and move the blocks below to make an empty space through which you can move.
8.4 A room full of concrete blocks that you need to move with the switches in room 8.3 to clear a path for yourself.