I would bring back the old feeling of RE, the quiet subtleness, dark atmosphere, and ZOMBIES. By todays standards, the game would have to update from the classic games. But not like RE 5, which was a good action game, but not only did it stray completely from the original RE, it completely lacked in soul. I could only play it once b/c I was completely bored by it. It's fast paced action was actually annoying, it felt like a war game. I would have action in the game, of course. But not like in RE 5.
Like I said, zombies would be back, but they would be scarier. Maybe a little faster and more grotesque. But no running zombies or zombies that use weapons. Also, the tyrants would be more freaky, like the monsters from "RE Revelations" or "Dead Space". No man eating fish or giants or something corny like that. I would have all the old characters, Chris, Jill, Claire, and Leon. And you would be able to play as different characters, with completely different scenarios and special moves. I like the inventory from RE 4, so I would keep that. Seeing as the characters have evolved, and have become more tactical, they would have cool guns and be awesome in combat, but I would make the weapons harder to come by. I think that RE 4 was awesome for introducing the merchant and allowing you to buy weapons. But I would make it to where you can buy items at the end of every level, and not have such a huge variety. They would mainly be standard weapons that you would actually carry around, pistols, magnums, machine guns, some grenades, rifles, shotguns, and of course, the knife. I would add a little more hand combat. Being able to kick, punch, and use some stealth moves, mainly to get out of tight spots. Also, ammo would me more scarce. Controlling your characters would be similar to RE 5, but I would make it to where you can walk and shoot. The camera would be over the shoulder like RE 4/5, but you can switch angles a little and continue to play that angle if you want to. The storyline would again evolve around Wesker, who btw wouldn't be dead. His so called death in RE5 was ridiculous. He is WESKER, the mastermind behind RE. He should be harder to kill than that! He would definately return.
So I would bring back the roots of RE, but add more modern elements, mainly to spice it up a little. The game would be more survival horror and less action/shooter. There would still be action, of course, but not war-like. The quiet score and creepy sounds of the old RE would return, adding to the fear elemant of the franchise. There would be more scares and more horrifying monsters. The setting would be very dark and eerie. And there would be really terrifying sequences...I would really want the game to scare the hell out of you. I would lose the war game feeling, there would be no monsters shooting at you and there would be no fast paced action score. The look and feel would strickly be classic RE.