As someone who has completed RE4 more than 4 times, I can say that this is an incredibly cool game!
1) Gameplay: The game doesn't confuse you with screamers, it scares you with its atmosphere. There are many zombies, they are strong, they are different. The game consists of several roughly speaking acts. And in each such act there are completely different opponents. At the beginning you fight with ordinary villagers, and at the end armored soldiers with machine guns come against you.
After some time in the game, you have a partner, Ashley, but she won’t take a gun and start shooting zombies with you, no, she’s just an ordinary fragile schoolgirl who needs to be protected. Zombies often don't want to kill her, they want to kidnap Ashley. But don’t think that it is useless, it helps in some cases to open the door. There are also levels where you play as Ashley, but there are very few of them.
The game has a lot of additional modes. There are several additional small companies. And one survival mode.
2) Graphics: Looks good for 2005. But even in 2020 it is quite playable.
3) The plot is simple to the point of disgrace. You are an agent and you are saving the president's daughter. But throughout the stories you meet interesting and colorful characters. A bald big man in a cloak who does everything to kill you, a petty prince in his personal castle, and so on.
4) Controls: This is a very important part of RE4. You are not as agile as in RE6, you move slowly. The developers call this control "tank"
You are always afraid that someone is behind you. When more than 5 zombies attack you, you start to panic.
5) Music: There is not much music here, but the background sounds really get on your nerves.
6) Multiplayer: It's not here.
7) The voice acting is very good. The English voices are well chosen. All sound appropriate. But I would recommend playing in Japanese, after all, the native language for the game. And don’t play with the unofficial Russian voice acting, it’s too funny. So for the first time play in English, and then when you replay (and you will) play in Japanese.
If you want a good and atmospheric game. Which always offers you something new. Then be sure to go through Resident Evil 4.