Though some things are lost from the first game, it's still a fun ride worth taking.
In Prototype 2 you play as Sgt. James Heller, a man bent on revenge for the murder of his wife and daughter, presumably at the hands of P1's protagonist, Alex Mercer. It's not long before Heller is 'recruited' in a sense, by Alex to fight who he deems is the real enemy, Blackwatch. Over the course of the game you will be constantly upgrading Heller with more and more vicious and outrageous biological weapons. Most of these upgrades will come from vanquishing and consuming infected targets throughout the world. While the game isn't heavy on story or big on mission variety, it's enough to keep you playing through until the end. It's no surprise that due to this, the best way to play is to treat the story as nothing more than a series of events that just so happen to take place in an open world playground of destruction.. and you will be causing a lot of it. Simply put, if that isn't your thing and you require a more polished brand of story telling and more innovative mission design, then you're better off with something like Batman: Arkham City or Assasin's Creed. If you're into open world games where you become an insanely powerful apex predator capable of inflicting insane amounts of chaos, then you're in the right place.
Now that that's out of the way, I would like to outline some of the major changes from the first Prototype to the current game. Firstly, the locomotion system of parkour has been streamlined for ease of use. This may be a boon for casual players but you if you played the first game, you will find yourself missing some of the various ways of springing from building to building or vaulting across the city. The basics such as air dashing and gliding have been retained while some finer points such as wall sliding and climbing have been curiously removed altogether. While these seemed integral to the first game, it seems that an attempt was made to focus more on the action. As such, the new dual wield system delivers quicker action for using powers even if the system has been 'dumbed down' in terms of combos and novelty moves(ie. you can no longer pound your hammerfists together to create shockwaves or cannonball into crowds). Whether or not this is a good thing depends on how you played the first game. It seems Radical took this more focused approach since a criticism of the first game was that there were too many moves that people never used. While this has been addressed, I am personally sad to see that favorites such as 'Patsy' have also been removed. I feel that the extra moves gave the player more creative options should they choose to explore them. Rather than criticize, I applauded this aspect of the original game and was rather disappointed to see it go.
The gameworld of Prototype 2 is divided into three distinct zones. You will start out in the Yellow Quarantine Zone but soon move to the highly militarized Green Zone and finally the Red Zone, which has been completely overrun by infected masses. This is a big change from the first game where zones shifted from spot to spot on the map and it has it's ups and downs. On the upside the gameworld feels larger and more defined than the first. On the downside, some of the epic crossovers that resulted from having zones next to each other are lost. You will no longer see civilian cars crashing into infected hordes as brawlers chase down uninfected citizens while two goliath tanks pepper the area. In fact, the spawn points are no longer random in terms of tanks or brawlers, as a set number at a time are spawned around military bases and infected tentacles.
As you play you will be absorbing not only the appearances of your enemies but also in most cases, their memories. The memories you absorb have a very different tone this time around. In the Prototype 1 the memories you absorbed had a distinct vibe of secrecy. This conspiracy theme fit with the first game as it was the beginning of the outbreak and the arrival of Blackwatch. In Prototype 2 the memories don't have the same focus on the protagonist and in some cases might have been better off as simply mission briefings. Most of them comprise of back and forth chatter between military personnel that may or may not be relevant to your current objective. The previous game's Web Of Intrigue that helped define the nature of the virus and revealed more about it's origins and biology as well as top secret information has been replaced by //Blacknet which unfortunately isn't hardly as intriguing.
Some of these differences can easily be explained by the timeline and evolution of the game as it moves the player from the perspective of Alex Mercer to that of James Heller. Perhaps Heller doesn't have time for all the little style points that Mercer accumulated and maybe it's less chaotic because by this point because almost no one in the red zone is uninfected(though the story says otherwise). Still, it's worth playing through to the end of the story progression for a chance to face off against Mercer for a fight worthy of the hype. Even if your Heller has become so powerful Mercer can barely touch him, the final showdown is a sight to see.
Also included with pre-order copies is RadNet. It is accessed via code that can apparently still be obtained legally through purchase of copies dated before release or illegally through an online generator that has become very popular. So much for the limited exclusivity that Activision advertised. RadNet contains a set of challenges and events that are unlocked every few days and will continue until June 7. These events are like the ones in Prototype 1 only now your scores will be tallied against your friends with RadNet access. It feels as if these, challenges especially, should have been available for all as opposed to pre-order code. The mutations unlocked seem inconsequential after you have a fully evolved Heller, but there is one bonus however; Alex Mercer. Yes, after completing the various challenge sets up until June 7, you will be able to unlock a "mutation" skin to make Heller into Alex Mercer. One can only hope that this skin will include Mercer's fighting animations that he uses during the final showdown, and dare I say possibly some of his former locomotive abilities. The latter is probably reaching a bit far.
So, all in all Prototype 2 is a bit of a different beast than the first game. Fortunately the beast you control still provides load of fun to rampage through the streets of NYZ with. It's an experience that it worth the cost of admission and may have you coming back weeks later for another helping of bio flesh pudding. =]