I get your point, but did you also have fun with the game? I always felt the need to go back and beat the game multiple times. It's usually scary the first time around, but then it becomes more fun and more along of an action game. I mean, I did enjoy blowing the zombies on my second playthrough.
Lowering the ammo would be great. Making the game darker as in lighting and visibility is a good plus. Make the enemies fast would be a nice twist. Enhance the sound quality of growling, grunting, oozing and all that jazz can help. Allow random zombie revival would be a nice twist as well. Then to top it all off make it so giant B.O.W.'s with massive health attack at random points of the game forcing you to run and leave the area or hide.
To me that would be a survival game and RE at a prime.
To me, going back to roots in RE6 trailer meant taking elements from every game.
RE1: That President Zombie. RE2: Leon in Raccoon City type setting, Hulk. Think Ada will show up too. RE3: Hulking Nemesis type enemy [which was kinda in RE4 and RE5, only not persistent throughout the game] RE4: Krauser type merc frenemy. RE5: Co-op. Wesker type enemy [well, Krauser was that too], mix of classic and new BOWs.
Playing Borderlands GOTY: Lilith-66-PT2.5, Roland-15, Mordecai-11, Brick-7.