Lots of good observation here, though I find myself strangely compelled to defend the Hannah Montana video game and its ilk. I'm not sure why; maybe just because I'm argumentative and haven't had any caffeine yet today?
Let's face it, Hannah Montana is popular; skinning games with popular entertainment tie-ins is an old practice. Pretty much every major entertainment franchise has its games, from the Matrix to Star Wars to Avatar: The Last Airbender to X-Men to Ben 10 to Kim Possible... you get the picture. It keeps happening because it moves games off the shelves.
And here's where I get to the part that's bothering me. (Note that I'm extrapolating from what the author of my linked post said -- I haven't actually played either one of these games, and I don't know if she has either. So I'm arguing against myself, here, and not against her.) The suggestion that a Hannah Montana game (and in the past, Mary Kate and Ashley games) is an inferior game on the grounds that it's skinned with a theme popular with the tween-girl demographic is a pretty big assumption. And it's an unfair, sexist assumption, too.
First, even if you just don't buy into the popular franchise the game ties into, that doesn't mean the game is bad. Maybe it's just not your cup of tea. And even for a phenomenal franchise, if the underlying structure of the game is flawed, the game still sucks (E.T., anyone?).
Worse, the idea that a game built upon a wildly popular girls' franchise must be a pretty weak game? That's exactly the sort of thinking that creates that "oh, but girls don't play games" construct in the first place. Girls DO like Hannah Montana. If you make a Hannah Montana game, some girls will play it, and bing! you have some more girl gamers. Isn't that the whole idea? Why do we have to provide girls, not just with games that appeal to them, but games that have some sort of moral authority, too? The game is selling, so it does actually have that appeal. What's wrong with that? Why is it OK for a boy to want to play Spider-Man and it's not OK for a girl to want to play Hannah Montana?
I'm not saying the Hannah Montana game is objectively fantastic, mind you, or that game developers can't or shouldn't do better. Franchise games often feel like they're phoned in, whether they're aimed at girls or no. And Hannah Montana does have the token girl-game element where you can design outfits and unlock Hannah's wardrobe... but it's not a game revolving entirely around shopping and fashion, which is the real problem with the games-for-girls space.
Oh, and... if any of you have played the Hannah Montana game... let me know what you think, 'k?