Well, I'm 9 and I'm allowed to play it. But you might need to think of how your kid reacts to stuff. Like this. Green - Doesn't get messages, no nightmares, doesn't react badly, doesn't cry. (they may need to cover eyes at scary scenes, and sometimes they may need to get somebody to play part of the game for them, because some of this game is really scary.)
Yellow - Doesn't get messages, tiny nightmares, reacts OK with the blood and scariness, tears.
Red - OFF. Don't let these children watch or play this game if they: have bad nightmares, get messages from games and TV, reacts badly and screams, cries badly.
There are to tips for Resident Evil 4. The best RE4 games is for the Wii Console, always try that first.
P.S. Here is a list of the enemies that are in the game and may be frightening for children.
Villagers = Bit Scary (main enemy) - Men or Women with Axes, Pitchforks, Dynamite, Hatchets, Sickles, and Knives.
Del Lago = Bit Scary (Boss) - Big Whale-Like Creature.
El Gigante - Scary (Boss) - Big Giant.
Zealots = Scary (main enemy) - Different men that wear robes, goat masks, and bullet proof helmets, while carrying scythes, flails, crossbows, and wooden shields while others carry dynamite and rocket launchers. They ALL growl and Mumble words in a deep voice such as "Die,Die,Die" and "To die is to live" all in Spanish. Others wear tattoos on their faces, and have red veins shown.
Soldiers = Scary (main enemy) - Men that carry stun rods, flails, wooden shields, RPGs, dynamite, crossbows,big hammers and bullet-proof helmets.
Bitores Mendez - Transformed Villagers that have a crab like head and try to shred open Leon.
Dr. Salvador = Scary - Men that carry chainsaws
Bella Sisters - Very Scary Group of 2 Women that carry chainsaws
Novistador - Very Scary - Big Creatures that use their claws to scratch and can turn invisible.
Colmillos - Scary / Very Scary - Dogs that use their teeth and claws to rip open your throat when you get near. Some dogs you meet may not have tentacles, acting like a mad guard dog. Others have the tentacles coming from the back and mouth of the dog and make them Very Scary.
Armadura - Very Scary - Knights that make loud noises and have big broadswords and usually appear in dark places.
Garrador - VERY Scary - Tall blind men that rely on sense and hearing with knife fingers and have deadly attacks such as swinging it's claws, charges and impales target, and swings and connect Leon with its claws and slice his head off. Ouch.
Regenerator - Too Scary - are human-like infected creatures that carry many parasites and can stretch their arms and kill Leon when caught. They also breath weirdly, and do five noted breaths. When heard, and they get closer, it gets louder.
Iron Maiden - Too Scary - Just like the Regenerator, it's even scarier, faster, and has way more parasites. Bigger claws, and scary actions, makes this a very scary enemy in this game.
U3 - Too Scary - Pink creatures that can use thier claws to slice open the player and kill in one slice, sometimes.
Verdugo - Too Scary - Tall Creatures that have robes and have sharp blades to rip open Leon, like many of the other creatures.
Jack Krauser + Transformed - Too Scary (Boss) - Jack boss, and him transformed with a red glowing arm that can choke and tear through Leon.
Salvador (Tranformed) - Scary (Final Boss) - Salvador transfromed into a Crab shaped creature with Salvador hanging and the crab being his head, this is a great Final Boss.
So, it is TOO scary for you? You should really try it out. And again, try the Wii Version first. I really hop this was helpful, because this took me a while to do!