My English is terribly poor...but some clues are here.
I think that the powerful charm of an escape game is sense of accomplishment when you resolved the riddle by oneself .
Therefore even if I says a clue, it is a vague one.
Basics of escape

*Let's watch and touch the item in detail screen first when you obtained it.
*Let's open every object that seem to be able to open.
*Let's look in every places that seem to be able to look in.
*When only the center of a screen and an outstanding place look, you may overlook something.
*In the place without a thing to get,let's particularly try to look.
*I recommend that you utilize a save function if stuck. Possibly you may understand or notice something by pausing a little.
Clues from here
* There are some balls, how do I use them?
You do not use it at first, but let's pick it up if you find it, because that is important item.(this game name is sphere :)
* I can't open the first box.
When you examine a desk from various angles, a clue may be found.
* I found a memo. However, I can't open the box.
The memo seems to be a part of something, let's compare them well.
* Though I watched among rooms and got some items, I never advance.
Let's observe the wall of hanged houseplant.
* I do not understand how I use a red pencil.
I use it for writing and painting. Didn't you see the blank paper or note?
* I do not understand how I use a white box.
A book of a desk is just a clue. At first let's try to tinker with it with a detailed screen. An electric bulb means a light.
* I do not understand a puzzle of a color.
Somewhere, there are items same as a button color or pattern. Let's confirm your items in a detailed screen and try to look for the room well.
* I think that the color and the pattern of the puzzle are correct certainly, but there is no reaction.
Let's try to compare a picture of a button with items well. Is it a rabbit?
* What is a brown lump?
In a book of a desk a clue. Let's do it according to a picture. But you have to solve an at first-colored puzzle.
* How should I use a brown lump? (I solved puzzle...)
As in the picture, water is important and combine some items.
* A box of a number does not open.
Is not there any place worried about? I recommend that you clean it.
* I can't fix the board to the seesaw.
If you merely put it, it will come off easily. Don't touch itself after having put it, but have the seesaw base.
* A meaning of a seesaw?
It is a scale. If weight of right and left is the same, the scale balances.(Some parts are needed before using the seesaw.)
A green doll how?
Let's watch the foot.
* Where are balls?
It may be hidden in a background of a similar color. Let's open all boxes and all drawers.
*Where is golden ball?
Golden ball is not in room. A photograph and seesaw tell you the weight.
* I can't solve the wall puzzle.(1)
A blank opens for a ball. (=) means right and left are equal. Let's use the seesaw perfectly and try to examine relations of weight of balls.
* I can't solve the wall puzzle.(2)
Temporarily think that lightest ball weight is 1. And lead the weight number of other balls.
* I can't solve the wall puzzle.(3)
I think that it is more easy to understand in order of the second, fourth.