It's simply an updated version of Monster Hunter 1.
You start as a hunter, you will have to provide your small village with food and such. It's hard, the cover of the game doesn't lie. You'll find mammoths, dragons etc. Even one of the most common enemies are 2.5 times as large as you.
To fight them, you have a good choice of weapons. They're all unique. Huge swords, lances, bows etc. and my favourite; the Gunblade.
The gunblade is a gigantic cannon, which is almost equal to the gun of tank, its armed with a huge bayonet to fight in close combat. A jack of all trades, a master of none.
It's simply what you want to do.
Graphically, the game kicks perhaps every other game right in the balls. It simply looks awesome. It's full of style, huge mountains, forests, huge lakes.
A problem is though, you cant target enemies, it makes fighting sometimes a bit hard. The camera isn't horrible, but it isn't good either. But the game itself is good, and you'll get over it.
Another problem is that it takes lotsa time. Lots of, you'll have to progress a lot before you can take on the real deal, so it makes the game a bit hard. But well, it will become addicting.
If you're that kind of person who travels a lot, and doesn't mind playing Monster Hunter when at home, you'll love it. Simply love it.