The Graphics in the game are very good, not the best ever but visually some of the landscapes are stunning. Plus you can really push your graphics features (if you have Nvidia cards) to include soft shadows, TXAA and simulated animal fur to really add some polish to the game.
Gameplay is what we have come to expect from FPS games in recent years. It is almost identical to Farcry 3 in this respect (which is no bad thing) and the cover mechanic that I thought was great from FC3 returns for FC4. Furthermore, the ability to shoot from vehicles is a well implemented addition as it was previously lacking. Overall it is mechanically very solid and entertaining shooter, the weapons are satisfying and Kyrat is a wonderful open playground to explore.
The atmosphere and story are reasonable, the atmosphere as I previously noted is aided greatly by the visuals, but the actual plot is similar to FC3, a rebellion against an authoritarian regime. The protagonist is a little bland, and his back story leads to a ludo-narrative discourse, how can some average person attempting to return his mothers ashes to her homeland be a freedom fighter/ pilot / hunter / archer and mountaineer? This disconnect is not rare in games today, but I personally always find it jarring in terms of story.
Overall its a very polished, if not similar open world FPS. Usually this similarity to other games would lower my score, but the addition of co-op has pulled it firmly into the 80 out of 100 category.