Wow, I actually think Metroid Prime is significantly better than its Sequels (even though they are Good games). The pacing, the environmental variety, the world connectivity and the soundtrack all really sets it above the others.
Echoes is probably my least favorite but still Good, I remember thinking the art and the world just felt very bland, I didnt really enjoy the Light/Dark mechanics, thought the Dark world was a bit lazy with it just being the same room reused after an annoying loading screen. The Screw attack and bosses were fun but I hated how they gave it to you late game, it didnt see enough play.
Im currently playing Metroid Prime 3 for the first time and Im having alot of fun (im 70% through) its already my second favorite Prime game, I think it has a lot more interesting worlds to explore than Metroid Prime 2 but its somewhat linear, small and more disconnected making it feel less like a world, I dont think this really was a great move, to me this core to the Metroid Prime Experience but it is what it is. The motion controls work pretty well even though I prefer standard controls and it opens things up to some interesting enemy designs they can make for them and the grapple numbchuck mechanic can be pretty fun but I still think the game leans in too hard on them, theres alot of meh Gimmicks imo, I prefer my motion control usage to be very infrequent or not very involved personally. The boss's and lore have been really solid in this one though and Im glad you get the Screw Attack before the halfway mark this time so I actually can use it a little. One thing I think is a move in the right direction is how this game lets you use Energy Tanks for something other than health, it makes things less linear with decision making which is appreciated.
I think the biggest problems with the sequels so far is that they are pretty derivative in the wrong ways not really evolving older core mechanics in interesting ways and when they do something different it kind of leans away from what made the original such an Amazing game. My hope for Metroid Prime 4 is that they take big steps to Evolve Metroid Prime as a series, an Open World like Botw could do alot but I also hope they put new smart spins on some of the older moves that we havent seen before that really ADD and arent just a gimmick like Motion Controls. Also please give me something else besides Missile Upgrades, I hate that after the first 5 you feel nothing.