I can instantly tell that a game was developed in Japan by its User Interface. Often just the font gives it away (Japanese Devs seem to love serifs).

It's hard to describe, but Japanese developed games always seem to have all these shared characteristics. For example, inventory screens in Japanese games tend to be cluttered compared to similar screens created by western devs. Compare skyrim's inventory system to Dark Souls's and the difference is clear.

So why is this the case? Is it cultural, or some part of translating the game?

EDIT: Ohh boy. I guess people have different opinions about Skyrim's inventory system. Perhaps it's just built with consoles in mind and is more annoying on PC, but I find it very easy to use. The whole system is very minimalistic and based around straight lines and columns. Usually you can navigate quite a lot of stuff pretty quickly. In contrast, the Dark Souls inventory looks a lot more overwhelming on first glance and I've seen players rummage around though it for a while trying to equip different items. But, really this is just one opinion, and there are better examples being posed in the comments below.