Wow, lots of thoughts to add this week. Let's see...
Mario 3D World - Regarding the faster speed of the game, I think some of my favorite levels are the ones with the boost pads that make you super fast. There's one in the castle world (7 essentially) that's awesome. It's nothing but boost pads throughout the whole level. Two friends and I played multiplayer in that level and it was absolute madness. We decided to take turns bubbling so that one person could take a crack at getting the green stars at a time. It was a lot of fun, probably my favorite level so far.
I've played this entire game multiplayer up to this point (I'm in world 8 ), and I can totally confirm the fact that this game is, as James put it, "custom built to troll the crap out of people." Every level pretty much consists of us trying to pick each other up and throw them off a ledge, blasting really far ahead to troll people who want to explore, popping peoples' bubbles over pits, letting all the others do the work killing enemies and then snagging the reward for yourself, etc. All this is well and good for the most part, but it's kind of annoying because everyone shares lives, unlike in the NSMB series. They must have done that to try and discourage trolling (because if you kill someone else, you're just hurting yourself too) but in reality nobody really thinks that way.
As far as multiplayer camera control in that game, I can't make heads or tails of it. It doesn't have any immediately discernible rhyme or reason. It's certainly not the player with the gamepad, and it doesn't seem to be the person with the crown either. I never paid that much attention, but I seem to recall plenty of times where I had the crown but was off screen. I don't even think it's where the majority of people are going because oftentimes a single person would run off on their own and the camera would follow them for some reason. It's really hard to tell what the camera is going to do, which is probably my biggest complaint with this game. It makes it SO hard to play in multiplayer. But I've resigned myself to not caring about secrets while I play that way, which is fine because I would have to go through the levels twice most of the time anyway to get all the secrets, so the difference in experience with single player vs. multiplayer is a nice way to divide up my two playthroughs of all the levels.
One last note: playing the Plessie levels in multiplayer is pretty fun. Everyone has to work together to make it move in the correct direction, and I believe you jump higher if everyone jumps at the same time. For once in this game, cooperation is really necessary, and it's pretty fun.
Xenoblade - So glad (but not too surprised) that Guillaume is finally enjoying Xenoblade. It's such an awesome game, but I remember not being that wowed by it at first. I don't think it was until after the High Entia Tomb that I really started getting hooked (which I believe was about 30 hours into the game for me). That's a hell of a long time for the game to really get started! That's why I always tell people who are unimpressed with Xenoblade to give it more time. The farther you are into the game, the more complex it gets, with more characters, more systems, a more intriguing plot, more beautiful vistas, etc. It just keeps getting better and better (for the most part).
Honestly I was a little surprised to hear that Guillaume liked the sidequests. I thought that was one of the weakest aspects of the game. I would have preferred very few, but meaty sidequests with really big rewards (Chrono Trigger endgame style), rather than a thousand short quests with piddly little rewards. Also, requiring near maximum affinity with each area to get the extra skill trees, Monado Arts, etc. was not appreciated. SO. MUCH. BUSYWORK. I agree that it does help flesh out the world (aptly raising your affinity with that area), which is nice and one of the greatest appeals of this game, but I thought there were just too many of them. But I'm glad to hear that Guillaume enjoys that part because he's almost assuredly going to enjoy everything else then.
Also the inventory thing was my other complaint with the game. In a game as big and expansive as this, I think having limits on how much stuff you can hold is just unfair. I never knew when a specific collectable would be required for a sidequest, so I always got scared throwing things away. It's really an unnecessary stress that shouldn't be in the game. And as far as having too much equipment... the best stuff pretty much always sorts near the top of the list, so you shouldn't have to scroll through a bunch of pages whenever you're equipping things. And I never like to sell things in RPGs. Either it's too much work or I'm to paranoid to sell it off. I'd rather be safe than sorry. I wish Xenoblade didn't make me sell things off, but at least the equipment you get late game is strictly better than earlier stuff, so it's easy to let go of the old crap you don't need anymore.
Also, I found level I and II gems pretty worthless. Level III gems were moderately useful, but I only really felt level IV and V gems were totally worthwhile. That's more of and endgame and superboss type of thing anyway. I think the story is pretty easy (with the exception of THAT boss near the end of the game.... GRRRR) so gems can be pretty safely ignored if you find them a hassle. But at the same time, if you find yourself stuck, you could try messing with those instead of grinding if you prefer.
Playing as other characters is also one of my favorite aspects of the game. Each one plays very uniquely, and is also pretty balanced (as Gui mentioned, they all have ways to break, topple, daze etc.). I would frequently switch which character I was controlling just for fun, and I rarely, if ever, felt nerfed when doing so. Also, as Jonny briefly mentioned, Seven (name used by the community to avoid spoilers) is my favorite character to play. They became my main for the remainder of the game, and their playstyle is so fresh and fast and new that it gave me an entirely new appreciation for the combat, which had become kind of a ritual by that point (a good 50 hours into the game). The uniqueness of the characters and how well they're all suited to playability is another underappreciated aspect of the game that really made me love it even more.
Regarding the beauteous vistas in the game, I also loved how some of the best vistas in the game are secret areas. It's like a reward for truly exploring the areas. Not only do you get to see some of the most stunning views in the game, but you get a bucketload of experience at the same time. It's a fantastic way to make the moment feel like a special event. There are two in the game that stood out to me the most: one in Makna Forest and the other in The Fallen Arm. The latter in particular is after a long climb and feels like the end of a long journey. It also looks out across the entire area and really feels like you're on top of the world. It really leaves an impression.
Also, nerd note: Valak Mountain (the snow area) is not the head of the Bionis. The Eryth Sea is actually on its head. Valak mountain is the sword arm of the Bionis.
Jeez, I always tell myself I'm not going to write a book, but end up doing it anyway. I really have to learn to be more concise. : /
I was even going to write a spirited defense of the Gamecube controller, but I don't feel like doing that now. Maybe later I will if I can muster the effort.