Mario 64 not being widescreen is a minor gripe, and playing through the game I barely even noticed it let alone cared about it, but I don't understand why they didn't put in the effort to make it widescreen. The limited release is very stupid from a business and consumer perspective, but it only affects people who don't own Switch yet or don't have the money to buy it in the six month window, since I got the game day one it doesn't affect me.
The main reasonable complaint is the omission of Galaxy 2 in a collection that includes Galaxy, because that just makes no logical sense. If there had only been one Galaxy game and the second Wii Mario game was something else it would be fine, but splitting up the Galaxy games is just bizarre and feels intentionally underhanded. It'd be like releasing a Metroid Prime collection and only including the first two games!
And of course it would have been nice, considering they used the All-Stars branding, if they had packed this collection full of extra features and goodies, instead of just making a straight plain collection with a songs menu. The games all look, feel, and play amazing. The only reason to hate on the game itself is to fulfill the rampant "internet complaining" desire that lots of people seem to have these days. Nintendo could have actually put work into this and blown us away, but instead they went the lazy route and just gave us a plain but fantastic collection of Mario games that is an absolute join to play and well worth the price. It's disappointing because it could have been so much more, it could have been a love letter to fans, but for what it is, a simple collection of games, it doesn't get much better than three incredible Mario games.
People are probably mostly complaining because of expectations. If it hadn't leaked, and the first we heard of it was an official announcement saying they are releasing an HD collection of ports for the first 3 mario games, and they didn't use the All-Stars branding because the original All-Stars had a lot of extra work put into it, and they at the same time announced Galaxy 2 releasing separately at the same time because they decided four games was worth more than $60 or they just included it, there wouldn't really be anything to complain about because people wouldn't have let their imaginations fly with absurd ideas of the games being completely remade or something like that.
Yeah, I do think it would have been worth putting some extra effort in to make 64 widescreen. It didn't bother me at all while playing, but it feels odd when the other two games are now in 16:9 and this just...isn't. It's a strange move.
I'm not gonna lie, I feel the total opposite on Galaxy 2's omission. I from the get go, even when the rumors were going around, assumed Galaxy 2 wouldn't be included because it just doesn't make much sense. They're giving us three different types of Mario games with these three, and I feel like having Galaxy 2 in there would feel weird since it is largely very similar to the first Galaxy game. I'm not at all saying it SHOULDN'T be there, if it were I would have been very happy. But from that perspective I don't think it's really a glaring omission. We might see a separate release later though.
I definitely agree that most people got their hopes up due to the leaks. If this had been revealed with no prior knowledge of it happening, especially considering it was revealed only two weeks before launch, it would have been MUCH more exciting, and I don't think there would be AS MUCH complaining. (Still some lol) Even so, I don't understand why they didn't include any little bonuses. The soundtracks are nice and all, but I wish they gave us some more QoL features in the games, or even added in some new content. I like that the games look the same as the originals (I would hate them making every game look the same in the Odyssey engine or something, these each need their own distinct look) but retroactively putting Luigi in 64 or something small like that in each game would have made for some very neat surprises, and made it more exciting for those of us who have played these so many times before. Despite that, I still think it's more than worth full price, because these games are still absolutely amazing. But it is a bit disappointing it's lacking some of that.