NOTE: this game is extremely dark, you may need to adjust the brightnss on your monitor before playing.

After you read the letter turn left and pick up the rope lying on the ground.
Turn right and click the front left corner of the building.
Pick up the crowbar on the ground.
Click the left side of the building to get a view of three bricks protruding from the wall.
Push each brick once.
Turn right and enter the small opening.
Click the wheelbarrow and take the sickle hanging on the wall.
You can examine the file cabinet by moving the wheelbarrow.
Open the middle drawer and read another letter.
Zoom out and turn right to the grandfather clock.
Focus on the picture and click it to reveal the word Cthulhu.
Zoom out and look at the grandfather clock. (it has roman numerals and 4 circles surrounding the clock face)
Turn right, exit through the small opening and turn right again.
While facing the building examine the tombstone near the middle to see roman numerals inscribed on the tombstone.
IIIXX X
IXX XX
Go back to the grandfather clock.
Turn the clock hand to the IIIXX and click the top left circle.
Now, turn it to X and click the top right circle.
Turn it to IXX and click the bottom left circle.
For the last one, turn it to XX and click the bottom right circle.
Zoom out, if done correctly you will see something at the bottom of the grandfather clock.
Take the seal of R'Lyeh.
Exit the small opening and turn right two times.
Click the ground near the middle tombstone and use the sickle twice to reveal some writing.
Use crowbar and then rope to climb down.
Place the seal in the slot to the right of the door.
Click on iron door and your done...for now

I've moved the hand and clicked the pictures when the hand pointed at them but nothing happens.

On the grave stone in the middle when you are looking at the Uni from a distance