This game goes further than providing nostalgic pleasure.
I never played a Serious Sam game before,and this one reminded me why I started playing videogames and liking the genre of FPS.
It was like a flashback,but a good one.
And I don't know about you,but I like the way the game gets harder as you progress unlike most modern shooters where you can die or kill the same easy way on map 1 and map 8.
It reminded to me that I was playing a game that was made focusing on making me have fun,not that I was watching a directed movie where I have to press buttons to keep it playing..
The mechanics that consist of its gameplay,where you have to develop different tactics for different enemies kept me interested unlike for example BF3's campaign where no matter what the enemies carry, and on which level you are,you always have to do the same thing,cover,aim,shoot.
To progress it requires you to change the way you approach each situation and that keeps feeding your brain with the feeling of freshness,and I didn't felt it became dull or boring like I felt when I had completed about 5 missions in BF3.
If someone is interested more on a single player,I think he would have better experience with ss3 than bf3,but bf3 is all about multiplayer anyway.