Note: the voice comment was me running out of similarities, seriously, they have almost nothing in common. The best way for you would be to get your hands on a demo, or a demo of any of the games i listed (preferably not of mass effect, since the combat system is completely different). Other than that, DAO focuses on a stronger main quest with a certain degree of branching, appealing companions with well-worked personalities and dialogue, and strategic combat. DAO is NOT about free roaming. Compared to, say, oblivion, which is ABOUT free roaming and procrastinating, haves no companions, interesting dialogue or plot to speak of, and combat is about "action" more than strategy. Note, this is not game bashing, Oblivion does very well what it is about: exploration and free roaming; like any good sandbox game. DAO combat is not turn based per se, but you are controlling up to 4 characters, able to switch between them as you please, and combat can and should be paused whenever you feel like it to switch characters, assess the situation and queue actions as needed.