@shagge: I'm pretty bad at it too. I've played all the other games without too much trouble, but I don't think I've quite found this game's sweet spot between stealth and going loud.
I would say that the game is significantly easier than previous games because the alert phase is far less punishing (you can run away and hide really easily unless you are in the middle of a ton of guys) and it is much easier to save stealth in reflexes mode.
If you are having trouble, I would recommend climbing the watchtower in the warehouse and picking up the sniper rifle. Also, I found out today that it is entirely possible to kill every enemy in the entire base.

Log in to comment