The game itself is short (it took me 8 hours to finish it). It uses the same mechanics as Far Cry 3, but it's more like a shootout. It has funny moments, all the cliches are heard and you can laugh all the way. You have the opportunity to save the world and get the girl. You use different weapons which can be upgraded. In fact there's an island top be discovered and liberated.
If you follow the main plot (like I did), you'll get it done pretty fast.
A fun game to play though.