Thought I'd mention now that I have a bit of free time again (even more come next week when I'm a free agent again and don't have to do almost full-time work with full-time school), I managed to finish the game the other day while I should have been sleeping.
Overall, it was very damned good. There's not a whole lot new to report outside of my earlier impressions other than the game really came into it's own about half-way through as it more or less stopped doing as much hand-holding and the maps started to come together to form less isolated areas like I previously thought they were. It might have been just how I was approaching the game at that point because by then I gathered enough gear to really do some item hunting and the exploration came more into focus then. The spoon-feed context stuff also seemed to let up as well because, but that point, you were more or less at the front of the action and you were more actively discovering what was going on. There are a few exceptions, but that was the general rule through the last bits. I even managed to get a 100% item retrieval rate, something I've never managed to do with a Metroid. It should be noted, that it's far easier to do that in Corruption than other Metroids, but I don't think that's actually a bad thing since it's something that was only for the crazy people before.
My only real complaint was the ending felt a bit rushed, which is strange since the game was huge (I clocked in just shy of 20 hours) and there was tons of buildup towards the final battle. It was like you finally got there and everything settled itself rather quickly. While that isn't entirely uncommon for Metroid games, this felt a little more so, probably because the last boss battle was lacking compared to the fights you went through to get there (and compared to previous final bosses in Metroids).
When all is said and done, I still think Prime 2 is still my personal favorite of the bunch, even though they all have their strengths. Prime 1 remains the tightest of the three and maybe even had the coolest base weapons as Echo's weapons weren't as varied and Corruption opted out of weapon switching in favor of stacking weapons like Super Metroid. Echoes had the best areas with the most interesting puzzles, which are my favorite parts so that explains why its my favorite. Prime 3 excelled in giving out fanboy food by showing off some stuff you knew existed and (probably) wanted to see while rounding out the adventuring with more straight up gunplay.
There was definitely more focus fighting in Prime 3, which isn't surprising, and puzzles took a bit of a hit. It's still completely Metroid, so it's not like the stuff was lost; the experience was just more action oriented, which might be better or worse depending on what you prefer. The important thing is that it works just as well. The story/context is also more action focuses as you're not arriving on the scene long after everything went down like in previous Primes, but as events are happening… sort of like Super Metroid, but with more technology to beef up the story side of things. You don't have to figure out what happened so much as it's happening around you (or you’re causing it). Again, this just the general rule and there’s plenty of back story to uncover as you go through the game... it's probably almost half-half in reality, it’s just that this is less typical in the Primes. It should also be noted that there are areas that are more like Prime 1 and 2 in that you get there after fairly long after the major events occurred, but they’re outnumbered by areas with more immediate storylines. It's pretty cool that the game is big enough to have multiple approaches like this as well. It's not like these are drastically different feeling, but it is notable since setting is a huge part of Metroid games.
So yeah, I'm very happy with the experience. As a worthy Metroid it easy fits into my favorite game list. I'm looking forward to see how the series continues given that this really feels, as advertised, like the end of the Prime storyline. Hopefully it won't be another near decade wait like it was after Super Metroid.... and if it is, well, they left off on a very high note.