Just received Assassin's creed 2

Hello, I got Assassin's Creed 2 as a gift for the PS3. Well, the game looks awesome, never had a doubt about that. After playing it for a very very short time, I have some questions for those whom played it. Ok, so the beginning I thought was cool, I like the future setting and honestly, I can't believe it, the camera movement is great, in other words if I just walk from side to side the camera will automatically turn for me, I don't have to constantly use the analog stick. I love the analog stick, don't get me wrong, I use it for star wars unleashed demo and ninga gaiden demo but the camera moves automatically as well, so I can move that stick only when I want to/need to and for site seeing, but not limited to only using it such as in all gun shooters now a days.

Anyway, getting back to assassin's creed 2, the first mission was fighting with some people, then the second mission was to follow my brother to the doctor, now... the third mission... which is already pissing me off, is racing the brother to the church. You know, call me stupid or w/e but it seems like impossible, I'm assuming for new generation kids it should be easy, since they're all adrenalin masochist junkies (no pun intended) but the controls in grabbing and then following the brother who disappears quick is not so easy. Is there a way to bypass this stinking objective of racing the damn brother? lol

So, it doesn't let you continue until you finish that stinking third church brother racing quest, it re-starts and restarts, I can't go site seeing and punching defenseless people for the hell of it. My question is: is the game constantly like this, linear, and that it doesn't let you continue and resets until you complete the next quest, quest after quest? Or once you advance to assassin level, you are free to do whatever the heck you want and advance to the next mission in any order and/or at your own pace?

I just wanna relax, site see and have fun, a challenge stinks unless you are a masochist, or young and don't know any better. It's really stupid that the graphics now a days are superior and you can't enjoy them the way it should be or at least have two options in a game: having fun option and challenge junkie option, that way the game can be played as you please. Star wars unleashed is fun, easy, relaxing, and you can't hardly die, also I heard that Prince of persia you can't hardly die either, also heard of Kameo:Elements Of DArkness and prototype from this forum, wondering how easy these games are and if you folks have played them, please let me know.

Wondering if anyone can answer my assassin creed 2 question and recommend easy, fun games that you can't die, except shooters, hopefully the camera movement is not so retarded, assasin's creed's camera movement is alright, I can manually move it, but it's also automatic just like star wars unleashed and ninga gaiden, so that's awesome. thanks for any help