So far, Hard mode isn't too hard. I haven't played the other modes so I can't really compare em, but the only thing I've noticed is that I was low on HP a lot early on (med packs started getting harder to find, unless you buy them). That changed when I got better with the main gun.
Omae o korosu-Heero Yuy http://youtube.com/watch?v=80DtQD5BQ_A
You need to know how to manage your resources, if you're an excellent shot, but absolutely suck at resource management, you're dead. It's the same way if you're a horrible shot, but excel at managing, you're dead.
im playing the game on hard so far i havent had any real issues however i have died a few times trying to figure out the controls mostly "i think im still in the tutorial", but i do plan to change my suit to the one i downloaded "not scorpion but the other one"....that is once i figure out how to do that lol..
the games alot of fun and the atmospheres great, my wife jumped then yelled at me the first time i got attacked. playing a game where you cant just unload a dozen bullets into someone is different, and the fact that the very important statsis thingy does take energy to use is kind of unnerving.
(walls of emptiness connect all opposites) GT:MTPathy
I'm playing on medium because the achievements are the same between that and hard. I am able to melee most of my kills so far in the game using stasis so ammo preservation isn't really an issue if you're good with melee.
Personally, I always start games on on the normal setting, and then play through hard later. Though, I could probably play this on hard because I've always been good at being INCREDIBLY stingy with my inventory items (Resident Evil 4 comes to mind), and then reloading a save if something goes wrong (I missed my first shot on this guy? RELOAD!)...yeah, I'm kind of undecided, too.