Been playing Serious Sam 3: BFE for the last couple of days, haven't got too far yet, but wow i'm really having fun with it.
It's still familiar ground for people who played old school shooters (specially the other Serious Sam games) but they changed a couple of things to make it feel a like bit more like todays shooters such as some guns having iron or red dot sights, also the sledgehammer is a good weapon, it's powerful to take out most enemies in one blow and you can do three attacks with it a fast vertical swing, a horizontal but wider swing and a 360 horizontal swing in case you're surrounded, the special melee kills can also be very useful against enemies like the Kleer's and the larger arachnids they're not cheap to the point of being exploitable you pull those off against hordes you'll take a lot of damage while the animation is going despite the instant-kills moves being fast.
But at it's heart it's still the same horde killing fun that keeps you on your toes forcing you to constantly look around everywhere to make sure you won't get blindsided by your enemies just like the previous games, though it's not as colorful as First Encounter and not as good looking as other shooters out there the visuals have nice touches to it, it's rather understandable why the visuals aren't very good since the game has very large maps to fight in. The boss battles i've had so far have been really fun and challenging, the Warship for instance was pretty awesome.
Also the hippie and kids options to censor the blood are hilarious.