I've been banging away at this game now for about a month, accumulated nearly 120hrs of gameplay and I'm still only 74% done. This game is a masterpiece. End of.
Stunning graphics, over 200 sq km of free-roaming area to explore and annihilate, inventive and surprising ways of doing things, totally immersive action that quickly becomes addictive.
I like the idea of choosing between story mode, faction missions and general farting around. The missions are great fun to complete but sometimes it's a lot more satisfying to hijack a heli or a fighter jet, fly to another part of the map, HALO jump out of said aircraft and absolutely shaft your new destination. There's always something to do on Panau, be it head-job a General from 600m away and snigger to yourself as his subordinates scratch their arses, tear through the beautifully-rendered villages and compounds and reduce them to nothing, run people over in cars or on bikes... The possibilities of this game are endless. It's easy to pick up and the structure of the game is fantastic. I honestly can't find fault with this game, well, apart from it taking over my life for the past month but I can hardly say that's a bad thing.
If you enjoy hours of uninterrupted pandemonium then my advice is simple.
Get. This. Game.