A significant improvement from the first, Assassin's Creed II will suck you in and leave you feeling very satisfied
As we saw with the first AC, you still take the role of Desmond in the modern world. Lucy returns and breaks you out of Abstergo, bringing you into an assassin's lair to continue your work with Desmond's ancestors. This time around, it is with his Italian ancestor Ezio Auditore, the whimsical son of a banker during the mid- to late-fifteenth century (1400s). What you get is a long, provocative ride from the birth of Ezio in 1459 to his final mission in 1499, during which you will watch Ezio grow from a naive, skirt-chasing teen into a mature, intellectual adult.
There are numerous improvements from AC2's predecessor, particularly in the story. AC2 is more story driven than AC, putting more focus on Ezio, his family, and the connections between him, his targets, and assassins of both his time, and the past. With AC, Altair was blindly following orders from his master, with little care or understanding of the events behind them. But with AC2, Ezio has more personally invested in the events, as each action, each target, is directly a part of his own story. It all starts with his family's execution, which spurs the events that continue to expand to the point where Ezio is not only seeking vengeance, but also the prevention of future woes that may be brought upon other innocents.
Another upgrade is made with the general gameplay. This time around there is a monetary system, which allows the hiring of groups of people, purchasing of weaponry/armor, and purchasing upgrades to the villa (the headquarters for Ezio's endeavors). This provides greater incentives for working on side-quests and extras.
AC2 also introduces a "notoriety" system, where certain actions (i.e. killing people, stirring trouble with guards, etc.) can slowly fill his little notoriety meter, until it gets full and any guard that spots the assassin will immediately give chase, summoning other guards and trying to fight your character.
Beyond notoriety is the blending system. Now, blending is both use of courtesans (scantily-clad women) and crowds, in this context. You may hire groups of women to escort you (thus blending you in) as well as to distract any guards you encounter. This proves quite valuable when you come across areas heavily defended, and wish to avoid bloodshed. Even without the courtesans, however, you may still blend in. If you come across a group of moving people, you may simply join into their troupe, and sneak right into a guarded region unnoticed. There will be numerous points where blending is vitally necessary for completing successful missions.
AC2 also features a wider selection of weapons and armors. Instead of just boosting your health gauge, Ezio can also equip a greater variety of weapons: from poisoned hidden blades, to long swords, to axes, the list goes on, with upwards of 30 options to choose from; he may also equip different sets of armor, from the mere leather basics to the extravagant "Altair" set. All these make for great variation and excitement in the battle system, no longer limiting you to whether you land a hit or not.
This sequel also puts more action and variety into the gameplay. Throughout the story, as you enter different cities/towns, you may come across Assassin Tombs. These tombs rely on your puzzle solving skills, as well as your ability to figure out sequences of movements and actions. AC is no longer a thoughtless killing spree it seems.
Along with the tombs are numerous Assassination missions. You find pigeon cages with notes that ask for a particular assassination to be completed. You get a target, a brief description of the circumstances, and then set out to kill them, however you are able to. You get paid quite handsomely for these missions.
These side-missions allow for a greater depth to the game, instead of the cut-and-dry rescue and gather missions from AC. Information of assassination targets are gathered from checkpoints in the storyline, instead of from the streets, again adding to the improvement in the storyline as mentioned previously.
Overall, Assassin's Creed II creates a greater atmosphere, is more addictive, and will leave you in awe and the impressive advancements in the story, character development, and gameplay as a whole.
Thank you for reading :)