Originally Posted by BioMechanic
I'm not as far in as most of you, but I am far enough to tell that Echoes isn't better than Prime.
The main reason I say this is level design. While the environments are sharper and prettier than most of Prime's, they're more confusing to navigate, even with the map (as well as that's designed). I've even gotten stuck, literally stuck with no way to retrace my steps out of the room I've reached. An example would be the the seeker missile puzzle area. The first time you reach it, the only way out is to solve the puzzle. The areas feel overly convoluted in places, perhaps due to the light/dark thing.
There's more wondering where & how you're supposed to get somewhere, and the solution isn't always obvious, even after you discover it. I've blindly stumbled upon solutions more frequently than I'd like, which never happened in the original Prime. For that matter, I've also accidentally stumbled into power-ups much more often than before, rather than tracking them on my own. When this happens, the feeling of accomplishment is diminished.
Backtracking also takes much longer. There's less connection between areas as compared with the first Prime - there's more linear "unlock A to get to B" instead of the "unlock C to get back to A" stuff that happened so much in the last game.
The areas of Aether feel more separated than the cohesiveness of Tallon IV.
All this said, Echoes is still the best game I've played this year. As good as the Prime games are, I'd love to see what Retro would do with an original idea.
One more thing: I think this, and the first Prime, are definitely replayable, for the same reasons that people listen to favorite CDs and watch favorite movies multiple times: for the details, and for how it makes you feel.
I am planning to revisit the first Prime once I finish Echoes, and it'll be my fourth playthrough. I'm not interested in speed runs - I'm more interested in enjoying being in those places. It's a longish game, but I think it's that good.