@Sven Groot: It's less about how long it takes to save/restore state, so much as how quickly you can get back to feeling "usable" again. It's a matter of reducing state restoration on start to exactly what you need to get back to a workable state quickly, pulling any remainder in asynchronously or on-demand as required. There are very few cases where it's quite as pathological a problem as with Remote Desktop (and even that could probably do better with improvements to the underlying protocol).
I'm not much of a Pinball player but I can't actually get it to do that on my machine (despite launching every Office app, Zune, Visual Studio and having a few games of Minesweeper and Freecell in between). I've got a lot of ram in this machine though, so it's hard to say whether that's atypical. I just find it switches to the "Paused" screen, which seems sensible enough, though I think it'd be less jarring if it was a paused state showing the game in-play and could be un-paused by pressing one of the keys. I'd completely agree about the intro sequence though, it's one of those horrible advertising travesties that only games publishers seem to think is a good idea. Doing that is very much against the spirit of Metro and in the worse case scenario, leads to the kind of horrible experience you're seeing.