For those new to the Monster Hunter series (and I'm still very new to it myself), I can't really compare the overall structure of this game to anything else I can remember playing. The Wii demo was my first taste of the series and I enjoyed it so much that I went and bought a PSP and Monster Hunter Freedom Unite. I've put a little over 15 hours into MHFU and I still feel like a complete noob. I've only really gotten comfortable with two of the weapon types, the hammer and the long sword.
After 15 hours, I've only been able to improve 2 of my weapons to anything beyond a slight bump in stats. I've just now gotten comfortable fighting the Yian Kut Ku which is the first real monster I've fought. I've now gotten a felyne companion to fight alongside of me and two more in the kitchen. I'm now becoming comfortable making my own healing potions and mega potions though I haven't learned what item combines with what other item to make anything else. I've upgraded my garden using pokke points twice and planted a mushroom tree. And I've finished about half of the two star quests. I haven't attempted any guild or treasure hunting quests and have just recently unlocked the first training mission beyond the initial beginner training missions. Many of the folks in this thread will tell you I've just scratched the surface. Once again I'm 15 hours in.
This game is deep. And I love it.
I can completely understand how folks put over 200 hours into this game. It is just that good. Out of 58 boss monsters, I've fought only one of them. The first time I brought down the Yian Kut Ku, I was ecstatic. Last night when I beat the Kut Ku for the third time and finally got the flame sac I was needing for the Barbaroi Sword, I jumped up in bed and woke up my wife (who didn't share my same level of enthusiasm). I'm just now able to really wrap my mind around everything that's going on in this game, bombs/traps/cut vs. impact/growing crops/mining/fishing/getting piggy-rub buffs/etc.
Now most of you new folks will probably not take as long as me to get up to speed in this game. I'm known to be slow :lol . But my point is the Wii demo is like a drop in the bucket as far as the full game is concerned. Of course my only real experience with this series has come from the PSP version (not the upcoming Wii one) but from what most folks have posted in this thread, MHFU is to MH3 as Madden 09 is to Madden 10. They're not exact copies of each other, but still come from the same mold. My only concern is that when MH3 comes out, I won't be able to devote as much time as I'd like to both MHFU and MH3. This series can become a huge time sink.
Also, my take on how experience/leveling/skills works in MH...
You can equip ANY weapon or piece of armor you want at ANY time if you own it. This game does not work off of experience points or attributes as other games are accustomed to using. When you begin, you have access to one star quests. Once you complete all of the one star quests, two star quests open up. Once all of the two star quests are completed, three star quests are available to you, etc. etc. etc. And you can redo quests indefinitely. Now, to get the better armor or weapons, you must have the items to create them or to improve your current armor/weapons. You cannot get the better items to create the better weapons/armor until you complete the quest that either gives the item to you or has the monster you carve that item from. In other words, you can use "level four" armor at any time, no restrictions, except for the fact that level four quests must be available to you (you've completed all of level one, two and three quests) and you've successfully gathered/carved enough of the items from the level four quests to make the level four armor/weapons. Makes sense?