What kind of game is this in its single player mode? Is it worth buying to play alone? Thinking about picking this up.

It's a game that is better played online with other players, at least until you can get some worthy armor and weapons. The game can get quite difficult alone, but not impossible.

The online is still decently active if you know where to look. Might not be the most noob-friendly, though, but the early-game is easier to play alone than the end game (by far), so once you get to the point where you really start having trouble by yourself, you'll be at the point where you wouldn't be a burden online in terms of either knowledge or weaponry.

The single player is not bad at all, for what it's worth, just that some weapons later on can really turn into grindfests, which is where having other humans help you makes it both more fun and faster.

I'd say its a solid 50 hours of single player content, if not more...If you go online, thats another 100+ hours ^.^

I personally played through almost all of the single player content before even touching the multiplayer

I'm thinking this a pokemon/digimon/dragon quest type of game single player wise. Is that far off from what it actually is? I can't see myself playing a non smash bros game online.

Only having played Pokemon of those games, it is very far off.

Essentially it is a game composed of only boss fights. You pick a monster to hunt, then go out and fight it. These fights can last over thirty minutes and are often very challenging. You have full control over your character and you need to read the monster's moves to ensure you are able to avoid any attacks.

Additionally, when you defeat a monster, you can harvest some materials from its dead body (alternatively you can trap it alive for better rewards). These materials are used to build armor sets and weapons which in turn allow you to fight bigger and badder monsters.

As sundin said, it's an ARPG with heavy emphasis on the A. Your character has an array of actions that are all performed in real-time, and the boss monsters definitely attack in real-time as well, with great ferocity. So it plays like a God of War or Ninja Gaiden, except your "hero" is somewhat more realistic (less acrobatic, depending on the weapon you choose).