I beat every boss on my first or second go in Dread, bar the final one. That took quite a few attempts but once I had the timing and signposting down I could reach the final phase without even taking a hit. I struggled with every single boss in Super, and spent *days* trying to beat the plant boss and Ridley in Prime!
I think getting some of the upgrades in this, especially those that need dexterity for the shinesparking, is going to be bloody hard but honestly the only difficult bits in the entire game aside from them are the blue EMMI (until I figured the best place to stand) and the end boss. I found every other Metroid difficult even just wandering round, but here there’s nothing that can really kill you, even with no power ups - you can just walk past most things.