Note that the label on Klax is unique to the Japanese release.
Label is not the only thing that is unique to the Japanese Klax release. Cart itself is unique, as the game is not stored in the standard Lynx ROM chip. The ROM chip used for Japanese Klax is bulkier than the standard one, which forced Atari Japan to create a custom cart for this game. This custom cart has a square bulk in the back to fit the new ROM chip and has no Fuji logo. Here is a picture of both Western Klax (top) and Japanese Klax (bottom).
Manual and box art are also unique to the Japanese release of Klax, but the one I have available for trade is a loose cart, so no point in showing pictures of those items here.
There's no difference in gameplay or in-game graphics, AFAIK.
Actually there are two versions of Japanese Klax. One of them (the one I have available for trade) is identical to the Wester version in terms of content, but the other one shows notable differences such as the total absence of music and digitized sounds. That other version also lacks difficulty level selector. The specific differences are documented in this post from another thread: http://atariage.com/...ge/#entry893638
I can testify as to the veracity of these facts, as I own myself one of those rare variation carts. Both cart versions look very much the same to the casual eye, but the green around the contact pins seems to be a givaway sign. Here are both variants next to each other. Left one is the cart containing the standard version and right one is the cart containing the cut down version.
Again, the cart I have available for trade is the one containing the standard version of Klax, not the cut down version.
I didn't know about these. Is the only difference the manual?
Yes in the case of Shaghai and Gates of Zendocon. For the differences between Western and Japanese carts, you can read the above comments.
Edited by Juan Josť Torres, Sat Nov 3, 2018 7:15 PM.