Survival Horror-To-Action Ratio
For Example:
Resident Evil -
100% Survival Horror
0% Action.
It is the pioneer of this genre. And don't give me that crap about Alone in the Dark. That game sucked. RE1 is true daddy of this type of game and it inspired several clones and changed gaming forever.
Resident Evil 3 -
75% Action
25% Survival Horror
The Dodge mechanic, the ability to create your own Ammo, the pseudo-QTEs, the game was clearly oriented more towards combat.
Now I made this topic elsewhere to argue with RE nerds so you can continue that trend and only do RE games but if you would like you can also put in other games like...I dunno, some of the Onimushas or those Dead Space games which I never played but a lot of people used to praise back in the day for being "real horror".