honestly, this is a very subjective question and it really depends on what you consider important on a metroidvania. there can be really no difference at all or be totally different, especially if you tie the metroidvania genre to stuff like "it must be a 2D platformer" (which some people do)

I feel like there's a spectrum from "Action-Adventure" to "Metroidvania" Ocarina is square in the middle of that sliding scale, with other Zelda games tipping more towards "Action-Adventure" All I know is that I'm missing the Metroidvania elements when I play modern Zelda (BotW/TotK, even SS)

Sounds to me like mp4 is in the ocarina zone almost? I’m curious what your opinion of Echoes of Wisdom was!