Go right to the tunnel with 2 holes to the left
Go inside and get the orange-red key from the right side of the grate where the green water comes from
Back up
Go right (the water here is green with purplish edges)
Click the left side of the tunnel where the gray interior tunnel wall meets the bricks around the opening
Get the hook
Zoom in on the hole on that wall
Use the hook in it to get the long purple key
Back up
While looking at the tunnel and the hole, click the right edge where the water spills down -- get the first gold piece
Go right (the water here is green with bluish edges)
Use the purple key on the second drawer from the top
Get the second gold piece
Back up
Click the small hole in the wall to the upper left of the tunnel entrance
Get the third gold piece
Back up
Go inside the tunnel
Use the orange-red key on the small lock on the covered hole
Go into the hole
Click to the right of the opening that shows the ladder
Get the fourth gold piece
Back up once
Click the top of the ladder to look up
Place the gold pieces
Click the opening to escape!

1- in crack by drawer view
2- to right of ladder
3-to right of green purple slime
4- in 2nd drawer