The story is... Just enough to justify the gameplay. You are essentially part of an organization colonizing a new continent. There are gigantic, dangerous monsters in the way. The plot is basically just saying that some sort of unnatural energy is causing the monsters to be too big and bad so they are threatening the entire natural ecosystem. The fact that the colony benefits from hunting them too is purely coincidental.
The game is pretty good, but I'd say a bit too complicated. Monster Hunter has built up systems throughout its life. I've not played any others but I've heard from people who have that World simplified a lot. Maybe it did, but there's a LOT of different systems at play that are quite complicated. There's a huge learning curve to all the systems and the mechanics of your weapons. I needed to lol up a lot on wikis and watch instructional videos.
The game looks and sounds good. The combat is similar to Dark Souls: a lot of dodge-rolls to get invincibility frames while you wait for an opening to attack. Your attacks (with most weapons) are combos like a fighting game.
It's pretty good, but not a casual game to pick up.