you are missing the point
that example you used is actually showing you are missing the point
New Super Mario brothers included NEW things on top of a working system where the controls are good, and the gimmicks don't really badly affect the game to the point you can beat a level without power ups.
Actually thats the thing about Super Mario…they tend to give us good things upon a good system, though its why for the RPG series specifically the paper mario RPG series…fans dislike anything past 1000 year door cause of the gimmicks are shitty and its not really fun when the RPG part was removed…but why folks can still enjoy the Mario and Luigi RPG series as it still plays as an RPG with new things being added to its enjoyment though each have its problems its still an enjoyable series.
Sonic 4 on the other hand didnt…
it controlled badly
you had to use the gimmicks to get thru the level instead of it being used to open up alternate ways to beat a level…
Its why the 3D game generations are divided between Dreamcast Generation where that generation wants games that was like Sonic Adventure and Sonic Adventure 2 and the modern generation that showed they enjoy gameplay that was of the Day missions of Sonic Unleashed/Colours/Generations.
Sonic 4 Tried to be that game for the Genesis generation but it didnt play as something of that time. We know it tried but just fell flat of our expectations of controls of that time of being quite responsive and the fact we could beat those games without needing our partner
the NEW Super Mario bros games did play as similar to the Nes/Snes type games…