Stronghold 3 is a literal tower defense game. You build a tower (or a whole castle) and then defend it from enemies with siege weapons that appear to be lobbing ******* bombs at the walls - or at least that's what this video makes it look like. I don't know much about medieval warfare (outside of A Song of Ice and Fire), but I'm pretty sure one projectile flung at a castle wall by a trebuchet or catapult couldn't make it explode in a spray of stone and body parts like it had been hit by a cruise missile. But then, who needs realism when you can make your game more awesome instead, right?