The Monster Hunter series is enormously popular in Japan. We're talking Grand Theft Auto levels of popularity. But in the west? Not so much. There's a strong cult following that lives and breathes all things Monster Hunter related, but sales just haven't been able to match those in the game's home turf.
Enter Monster Hunter 4 Ultimate, the Monster Hunter game made for people who haven't played Monster Hunter. Through catchy weapons tutorials, bountiful help options, and a smart progression of difficulty, 4U is the easiest Monster Hunter game to get into. If the series always seemed too stuffy or complicated, 4U will change your mind. And thanks to the miracle of intelligent game design, 4U does all of this without diluting the core combat/crafting mechanics that make it such a perfect co-op game.
In a scatternut shell, Monster Hunter is a third person action/RPG game that turns you loose in a world filled with materials to gather, monsters to fight, ores to mine, weapons and armor to create, and gigantic beasts to slay. Your hunter character doesn't have set stats or even level up on his or her own. Instead, you use the materials you gain from completing quests to craft better items and equipment, giving you a slight edge in the fights to come. Once you have that edge you can take on more difficult foes, hauling their spoils back to make even better items, and so on. It's a cycle that never completes, but that's exactly what will suck you in and keep you hooked for hundreds upon hundreds of hours.
4U does a little more in the way of storytelling than previous Monster Hunter games. Before, simple plots like "hurt the monster that hurt you" or "save the town from a big thing" were all you had to go on. This time, you start out as an unknown hunter joining the crew of a traveling sandship, the Capital C. Leading this boat is your new buddy, a caravaneer with an eccentric red hat and a personality to match. He's got this strange monster scale, you see, and he'd love to find out more about it. This provides some early motivation for taking on quests, but as the story develops, you'll travel to new towns, fight new and horrendous monsters, and meet lots of NPCs who have a flair for the dramatic.
The basic idea behind Monster Hunter hasn't changed in 4U, even though you have multiple towns to visit instead of one simple home base. Every village has an armorsmith, an item marketplace, a home for you to manage your equipment in, a place to sit and have a meal, and a guildmarm loaded with new quests. Instead of item farms and Granny Go-To, 4U has combined them into the traveling Wyporium. This strange booth is run by an old loon who has access to goods from around the globe. Through him you can "multiply" items, which is essentially the same as farming, trade points for items, or trade items for otherwise unobtainable items. The latter feature is a clever way to add more equipment to 4U than the number of monsters allows. Even though you can't fight Ludroth in 4U, you can still trade for his parts and make some classic Ludroth weapons and armor sets.
Another feature in 4U is monster mounting. Before your imagination runs off into rule 34 territory, mounting is a new mechanic that lets hunters leap off of ledges and attack beasts with the chance of riding on their back like a rodeo cowboy. If a mount is successful, a simple button tapping mini-game proceeds wherein the hunter tries to topple the monster before being thrown off. If that works out, the beast is tripped, opening the gates for the hunting party to do some serious damage.