With all honesty, I do like the layout and how you can move area to area more smoothly. It is a little confusing at first, but a little exploring it was pretty simple to grasp. The one thing I do prefer keeping, as another player mentioned, is the loot button on the side to see all loot-able objects.
I think the whole key concept is pointless, you can never get more than one so instead open all doors unless there are enemies in the room, its kind of annoying that i have to keep running to the opposite side of the room every time to pick up a key then run to the other side of the room to unlock the door
Hey, i just thought of something, why don't you give some options for the survival modes, like allow some soldiers to support you but they have a limited amount of ammo or something o.o