3. Player Class Impacts The World
Essentially, the only thing choosing whether you were a Soldier, Infiltrator, Adept etc. dictated was what one button's action then became. Some of the abilities were immensely fun - like the Vanguard's zip across the battlefield before ramming full-force into an enemy and following up with a finishing shotgun-blast - whereas others like the Infiltrator's cloaking abilities were ultimately pointless. When every showdown is comprised of trading fire, the idea of sneaking behind enemy lines is tantamount to suicide. One game that took the idea of class-based play and iterated on it perfectly was Deus Ex, with latest instalment Human Revolution still upholding series' traditions in that you'd be journeying through a level only to notice another path and note that if you had a certain ability, that's a direction you could go. Outside of combat and world-exploration there should be scope for your class to impact dialogue options, reassuring certain quest-givers that you can rescue a hostage safely if you're a soldier, attempt a stealthier approach if you're not, and have NPCs be more wary of your reputation in the field if you've become known for blasting the ear lobes off everything in sight.