It doesn't, sadly. It just reinstalls all your apps you've purchased. At Google I/O this year they did however unveil a way to devs to store your saved games in a secure section of google drive including features like conflict resolution (merging saves from 2 different devices). It's up to the devs to actually make use of these features however.

Not to let Firefox off the hook, but the link in that bug loads a tag list, which the page writer geniusly decided to non-breaking space the entire thing. It's essentially treating almost 1 Mbyte of text as a single word 90,000 letters long (850,000 including font sizing tags). I replaced one of the non-breaking spaces with a normal space and the page loads instantly and type ahead search works perfect.

You can't necessarily blame Firefox every time a web designer makes a bad choice.