Google announced an update to its Google Play mobile app on Android—its online store for apps, music, books, magazines, movies and TV shows—today, one that is aimed at cleaning up the UI and optimizing it for different device types. It’s a model of clarity and discoverability, not to mention scalability, features that are sorely lacking in Microsoft’s Windows Store.

To understand what I mean, consider the UI that’s currently available in the Google Play Store. Here’s what it looks like in the Nexus 4 (smart phone, left) and Nexus 7 (tablet, right) today. (Note: These are roughly resized by me, sorry if it's off.)

As you can see, they’re basically identical despite the fact that the screen sizes of the two devices is quite different. (That said, this design is still pretty clean.)

According to Google, it has redesigned the store with a design that is “simple, clean and — most importantly — helps you find great entertainment, fast.” But what sticks out to me is how the experience scales from smart phone to tablet. Again, here’s the view on the Nexus 4 (left) and Nexus 7 (right). (Note: These are roughly resized by me, sorry if it's off.)

Nice.

“Similarly themed content is grouped together so you can hone in on a magazine to read or an app to try,” Google group product manager Michael Siliski notes. “As you move down the page, new recommendations continue to appear so there is always more to see and explore. We’ve also simplified purchasing so you can breeze through checkout and get to enjoying your movie rental or other content.”

So how does Microsoft handle its online store?

In a word, poorly.

The Windows 8/RT experience is a space-wasting panoramic experience that extends wayyyyy past the viewport, to the right. By default, it looks like so:

Which isn’t bad. But you need to understand that that screen is just part of an unwieldy monster of a UI. If you could just have a display with a resolution of 20525 x 1080, you could see it all at once. It would look like so:

Seriously, Microsoft. This is the best you could do? Even a grid of topic areas at the front would help. In the app bar at least. Something.

Put simply, this is an example of a UI that does not scale, even within the confines of Windows 8/RT tablets and PCs.

By the way, the Windows Phone Store, like Google Play, offers multiple content types, not just apps (in this case, apps, games, music, and podcasts). But looking just at the apps bit, a better UI does emerge. It’s a panoramic experience, like the Windows Store experience on Windows 8/RT. It’s oriented to the usual portrait use case on phones, not to landscape as with Windows Store. But it provides obvious areas for discovering apps of different types via just a few screens.

(Sorry, I was too lazy to make another panorama view.)

Point being, it’s possible to find a UI that works. And if you look further at the Google Play update, you’ll see that it works in both portrait and landscape modes. So if you have a full-sized tablet, like the Nexus 10, it can look like so:

Come on, Microsoft. You can do better. Windows Store just doesn’t work. On any device.

Update: Check out Fixing Windows 8: What Semantic Zoom Should Look Like in Windows Store for a bit more on this topic.