I see at least 3 major things wrong with the current design of the new battle toads.
#1. The "edge" of the characters
Battle toads was known for being Quasi-edgy, it had a slight amount of Blood and violence and an exaggerated play style (your character moves turning into weapons/construction equipment) that looks to be poorly emulated if anything in this new one (sock puppet...really?)
it was quintessential "EXTREME" cheese .
#2 it suffers due to sidescroller gameplay mistakes
As previously mentioned, each gameplay vid (thus far) lacks the punch of the originals, A game like this is built upon excellent fighting mechanics, and these just look dull...
Also, from a game design perspective, having enemies who are a mixture of neon pink hues fight you on a neon background featuring nearly the same pallet, the entire game just ends up looking cheap, and more importantly is hard to follow with your eyes...
The 1st few games were no miracles when it came to the graphics but the devs understood that you can't let the player lose your character on the screen, these new designs get lost and look like eye noise, it's very easy to lose track of what's going on the screen.
#3 The character Designs
As far as the toads themselves I don't really like the new design, don't hate it, but it's part of the simple look of many tons today... I'm not a fan of that particular style but they're at least all identifiable, Even if they don't remotely resemble the battletoads of the past, at least they are all different, but the decent (not good)design ends there...
If you want to redesign the evil Queen, that's fine adaptations occur all the time, but this one simply takes it too far not only do we cover up everything that made the original evil Queen unique in her sexy buxom design, but the new 1 looks like a freaking child, some tiny little preteen hanging out in a weird suit fighting giant Toads and nowhere more than her design do you see how the artwork suffers.
It looks like it was drawn by a child, it's Just dull, the old evil Queen was never a great design, honestly she was fairly generic, that being said it was a million times better than this pathetic piece of garbage.