Interesting gameplay, fun while it lasts.
Then you add an open map, some cover mechanics, the usual set of secondary missions and a decent main plot, and BAM Red faction.
This game has two big issues though, and they become bigger the more you play.
First, the game is solely supported by the destructive gameplay, and once you get bored of blowing up things, you get bored of the game.I think more games should include destructible environments, but it should be something to spice up the game, not the basis of it.
And second, half-way through the game you become a colossal force of nature that can blow up pretty much anything in sight, so it feels like playing with cheats on and you get tired faster.
Still, It's a lot of fun for the first 10 hours, and that's a very good point.