Music for one. Not sure how I feel about Nero's new look. The overall atmosphere/look of the game isn't great. While I always thought it was a bit weird that people besides the main cast don't seem to exist in these games, I also kinda liked it? Hmm.....this is all very different. Not really a fan of Nero having a mechanical arm as I think the devil bringer looked cooler. Also don't like how Nero is the star with Dante in the background again. If this game came out a few years ago, I'd be fine with that, but it's been ten years since DMC4 and I really just want Dante back in the spotlight.
Part of me feels like this is all deliberate. By that, I mean the developers are intentionally making the trailer seem like something it's not and perhaps they might continue this with future trailers and gameplay. Nero's look in particular makes me think they were trying to take a jab at DmC as a sort of self-aware humor and also to mislead people into thinking "Well, crap, we're getting DmC2" before Nero shows up, revving his Red Queen, and confirming that no, this is indeed Devil May Cry 5. The funny thing is that DmC Dante's gameplay has similarities to Nero. They both have a grab mechanic, they lack a style system that defined DMC Dante's gameplay, their Devil Triggers are auras, and DmC Dante is implied to favor his left hand with Rebellion being positioned over his left shoulder while Nero is forced to use his left hand for Red Queen. Perhaps they were all coincidences, but DMC5 going back and choosing to make Nero resemble DmC Dante by giving him a shorter haircut and a more subdued outfit that isn't as elegant or flamboyant as his DMC4 outfit and it's even ragged like his red shirt and white undershirt are torn and worn which remind me of DmC Dante's kind of dirty-looking outfit and introducing DMC5 with him makes me wonder if this wasn't intentional.
With Nero being the introductory character of DMC5 and with the trailer showing stuff happening to him, happening because of him, and happening around him, it makes it seem like DMC5 is about Nero with Dante, Nico, Vergil, and whoever else being a part of his story. But the info on Capcom Unity says DMC5 is next chapter of the "Sons of Sparda" saga and that the announcement trailer focuses on Nero, but DMC5 will feature 3 playable characters. Pulling the same stunt again would probably **** off people. Nero is a main character of DMC, but DMC started with Dante, so sidelining Dante again would be the dumbest thing they could do with DMC5 and they already did that with DMC4 and kind of DMC2 where Dante didn't feel like Dante as he was in DMC1. Considering Vergil is back and is impacting Nero's life and Dante is shown returning, part of me feels like DMC5 is going to be about the story of the Sparda family. I haven't played Nier: Automata yet, but part of me also feels like they might be pulling the same thing where 2B/Nero is the spotlight of the games' previews, but the reality is that the story is actually about Nero, Dante, and Vergil to the point.
As for music choice, I wonder if they're trying to make it more distinct about which music style is associated with the characters. Dante, Nero, and Vergil had their own themes and so did Lady and Trish in DMC4: SE, but as far as I remember, they were all under the same DMC style of music. They might be pushing for Nero to have a more pop, electronic style and which some people said reminded them of Metal Gear Rising: Revengeance's music. It also fits thematically with Nero having an advanced prosthetic arm, so his music being like that works in my opinion. If they're doing that, then Dante is probably going to have the classic DMC sound of metal. That leaves Vergil where they could take his battle themes from DMC3 and make them into a unique style of music for him or perhaps something haunting, refined, and Gothic-sounding with a choir could work too. I have no idea how to describe what I'm thinking of for Vergil.