The plot of the game is its flaw. It's kind of predictable and the end calls for a continuation. Adan Jensen goes to Praha and try to unravel a plot that could bring the end of mankind. He goes and does lots of tasks for different NPC's. The tasks could be accomplished either stealthily or blazing with guns. You have different quests and these quests bring you upgrades, An important part of the hacking different computers or different doors that can make you access different ares. These areas bring you goodies. You have weapons that can be upgraded. You can craft different things.
Overall, it's a good game.