In addition to lighting

The camera can not mark the location of the enemy, and the door needs two steps, the first is half open state, two is fully open. These details make "ZERO HOUR" exceed R6 in terms of game fidelity, but in terms of gameplay may be greatly reduced. In the current game field, the game's fidelity seems to be the most concerned element, in fact, this requirement is very normal for players, after all, the higher the fidelity the stronger the sense of immersion.