I don't see a clue to the fifth level. At 150% magnification, the name of the game THE LOCK appears in a circle under the game. Does this matter for the code? The code consists of 10 letters. Is it one word or several words written together? Those who do not know English will probably not be able to open the fifth level? Can you tell me what to look for?
The answer is in English, but the phrase is famous around the world. There is no space button, because a space button is not needed.
There are no clues for that lock, which is a clue in itself.
I realize that it might be a little more difficult for people who don't know English, but it should still be possible.