very hard series. MP3 is my only prime game, and its a real bitch on the harder dificulties

Metroid Prime 1 gave me a great challenge in Hard mode, I loved every minute of it. Metroid Prime 2 was ball-breakingly tough on Hard. I only beat King Ing due to a random fluke. Metroid Prime 3's Hard mode was more on par with Prime 1's in that the bosses are the only real pain in the ass... and that you have to use Hypermode far more strategically.

I completed Metroid Prime 1 100% on hard mode without too much trouble. I died maybe once or twice. First playthrough on normal was hard though. Meta Ridley and Metroid Prime are bitches, and deep down in the Phazon Mines your primal survival instincts WILL kick in if you don't go well prepared.
I never played Metroid Prime 2 on hard, but I can tell it was difficult on normal. The boost ball boss can make you cry, and the underwater exploration in the swamp temple can be a pain because of certain enemies. Finally, Emperor Ing proved a worthy opponent. Dark Samus just required a trick.
I also never played Metroid Prime 3 on hard, but that game had plenty of nasty bosses on normal. The final boss can kill you by simply bashing into you, and Valhalla and the Pirate Homeworld can be very challenging.

Reading this thread, I can't wait until the Metroid Prime Collection so I can do a guide-less 100% hard-run of all three games directly after each other!

i thought mp3 was way too easy even on hyper i breezed through the game. that big golem boss did take a long time to beat, but i didnt get hurt too much, just long to kill. mp1 to me was easy. i thought mp2 was the hardest of the series but still pretty easy, boost guardian was the only struggle. overall to me its an easy series, but one of the best

what are all the diifficulty settings?

The last few bosses on MP1 were pretty hard (Omega Pirate/Ridley/Whatever the final bit was)... I think only the end of MP2 was difficult... and I don't recall MP3 being too difficult.

I beat them all though.

I think they are the right amount of hard. Some of the bosses are a challenge in all the games, but always doable with some practice. That Golem thingie in MP3 was maybe the hardest for me actually, had problems with the timing to make him take enough damage before he wiped me out, I died many, many times.

I remember when MP2 came out they said it was harder than MP1; but I didn't really feel it was that much different; could be that I had recently played through MP1 and so had good practice.

The hardest Metroid game for me is still Metroid 1, maybe it's the slighter stiffer controls or the fact that you always start with only 30 energy, but I can't beat it for the life of me. (Tho I never had the patience to learn it properly). Super Metroid was pretty easy, Fusion has some pretty nasty bosses, Zero Mission was less of a challenge.

Every time I play through a Metroid game I go look up a speed run video on the Net, and then I realize how much I truly suck.....people kill bosses that take me 5 minutes in like 10 seconds...

Alright, thanks for those impressions.

So far it seems that most people agree about the series being quite hard; some more, some less.

I was playing on normal difficulty in all the games of course. I played the first one quite far, I guess I had about 60 % when I quit the game (and I didn't do everything, so I assume I was not that far away from the end). I think I didn't even get stuck in Prime 1, but after The Wind Waker came out, I slowly stopped playing.

In Echoes I was stuck at the morph-ball boss, and seeing that some of you have mentioned that to be a hard fight I feel a little less bad about it now.

From what I've seen in Corruption though, it seems that it is really a bit easier than the other two. I had some trouble with Meta Ridley and Rudos or whatever his name was, but I have beaten two bosses in the first attempt already, one of them being the Golem. Apart from the boss fights, I haven't really faced something difficult yet.

What about the earlier games and Fusion? Are they as hard as Prime?

True words spoken.  That was a very tough part of the game.  There a save point right at the beginning of the Phazon Mines and there isn't another one until deep, deep within.  The path to the next one are filled with beam Pirates that don't hesitate to jump you.  Man that part was epic.

Yeah, it's a hard series. Emporer Ing in MP2 was insanely hard. I'd say harder than the final boss in MP1, though they both took many tries to beat. I don't remember dark Samus giving me too much hassle after Emporer Ing, though.

I can't even remember the boss to MP3, so it must not have been that much trouble. The giant golem with the orbs was kind of a pain at first.