If you like literal, non stop alien killing for hours on end and really, REALLY great destruction then you will enjoy the game. The destruction physics completely obliterate anything else out there, there's nothing like it. There's lots of explosions, lots of things being torn to bits, and there's a LOT of killing, almost all of it is aliens. It's also extremely linear.
There is pretty much no character development past "You are Mason, son of other Mason from the other game and some other guy is an asshole". Mason will remain completely and utterly stone faced to any situation he ever faces; nothing phases him as he is an unstopable, merciless more-than-human monster. While a single alien is deadly enough to kill trained soldiers with comical ease, Mason is able to effortlessly fight off hundreds with his hammer as it is capable of cleaving through anything as if it's made of rice paper, be it stone, metal, or flesh.
The magnet gun can level anything instantly. There's almost nothing it can't magnetize to, so stick it at the base of anything and click somewhere else and off it goes, even if it's a 3000 pound monster that's 10 feet tall.
That's more or less my experience after beating it on normal.