I don't know how much you've played, but I've heard someone describe it as an MMO without people all over the place and chat spam etc. Be prepared to do a bit of grinding, and be prepared for
boss fights large monsters to last 15 to 30 minutes, at least until you get more powerful weapons. If possible try to use a guide to find out what kind of armor sets and skills you want to suit the weapon you prefer. I've been using
Kiranico but in all likelihood we aren't going to have such an awesome spiffy site like that for MH4u, at least not for a while. In fact, one of the first things you want to do is decide what kind of weapon you prefer and stick with it for a while. Upgrading multiple weapons can become time consuming. That's what this game is about: killing large monsters for their parts and using those parts to craft better gear so you can fight tougher monsters. If you can find what weapon you like you can figure out what kind of armor best suits your weapon, as each armor set gives skills that improve things like dodging invincibility frames or how quickly weapons with charge-up attacks can charge to max power.
I personally like the lance. It's very simple because it only has a handful of attacks and its gimmick is passive unlike the switch axe, and charge blade, insect glaive etc. plus it gets a giant shield that can block nearly everything... and by that I mean everything but lasers. Everything from monsters roaring, monsters nudging you as they turn, house+ sized monsters charging or hipchecking you, explosions, giant vortexes of wind that would send lesser hunters hurling through the sky, fireballs twice your size from dragons, spit attacks from various monsters... pretty much lasers (plesioth and AOE gas attacks are the only things you can't block without the Guard Up skill. You can sit there facing a monster you've never encountered before with your shield up and they won't be able to do a single bit of damage to you, allowing you to watch their movement patterns and learn how they telegraph their attacks. By the way, any attack you can block you can counter-attack, making you very deadly and enabling you to do more than a 3-stab combo. You can even get skills that make it one of the more mobile weapons in the game with the use of evading, but that's probably something you'd want to learn after you've gotten the correct skills and are very comfortable with the weapon, I haven't even tried it yet.
But really, play around and figure out what you like =p
Oh, another important thing is that half the game is about preparation before a fight. It's not a bad idea to have a checklist of basic items to bring. There have been plenty of times where I've forgotten to take cool drinks to the desert at daytime, forgotten paintballs, forgotten whetstones etc.. You may even have to go out and collect items before you do an actual quest in case you're missing something.
I wouldn't mind a new thread, could even make it now considering it comes out in just a couple days.
EDIT: That Kiranico site I just linked? Well, between the time I made this post and just this very moment they updated their front page. Looks like there -will- be a Kiranico for MH4u =D
So purrrrrfectly
tasty useful~
Just wish it used the old page's color scheme, I like the darker color more than the light one.