A great game with a even greater personality.
The storyline is typical. Humanity is in danger, you must save it. It has some nice twists and turns to it especially at the end but it's nothing new or unexpected.
The difficulty is easy. Even on higher difficulty you can easily outsmart the AI and cut through their defenses with the right class and practice/endurance.
RPG-wise, it's not that much roleplaying. Sure it has great dialogue, but it misses the leveling up abilities and skill-centered focus of most great RPG's.
As mentioned above, the dialogue is pure epic. Best I have seen in any game I have played. Not only the dialogue, but also the companions and the other characters you meet. Almost all of them are interesting in some way, especially ones of non-human origin.
You can replay the game with the same character after you beat it, saving level and all. Which is a great addition, same with importing choices from ME1 into the game. Truly brilliant.
So many places to explore, so many side quests and resources to gather, and so much to fight, you won't be getting bored for awhile.