There are two new enemies that made it to this game that weren't in the original or Director's Cut: crimson heads and Lisa Trevor.

The M.O. disc reader devices in the lab resemble modified GameCube systems.

The boss battle with the giant mutated snake and the first encounter with the Tyrant are largely unchanged from the original. The boss battle with the giant shark has been changed from a typical battle to a puzzle. In the final battle, to prevent players from simply running in circles and shooting the Tyrant from afar (like they did in the original), the Tyrant was programmed to attack the NPCs, forcing the player to intervene and save them at the risk of their own lives.

In the room with the ceiling trap, when the camera views the floor from above, you can see and uncolored Umbrella logo in the center of the floor.

A full remake of the original Resident Evil (1996), the new version includes an altered mansion layout with brand new rooms and enemies and new plot elements that take into account developments in the later Resident Evil/Biohazard games.  

Crows will never attack the players if they walk. In some areas such as the gallery or the small staircase near Kenneth's body, the crows tolerate running but will attack if the players shoot at them.

This is the first Resident Evil game to have its title in dark styled lowercase letters.  All previous Resident Evil games in all versions and ports used red uppercase letters.

There is an ancient Greek text on both the wooden Emblem and the Gold Emblem. This text contains non-existing Greek words, but if you read it phonetically, in English it reads "While there is life, there is hope".

In January 2015, Capcom released a HD version of this game under the name Resident Evil HD Remaster (2015), which is the 8th version of the first Resident Evil game, following the original PlayStation 1 version, the Sega Saturn port, the PC port, the Director's Cut for PlayStation, the Dual Shock version for PlayStation, the Nintendo DS remake and the officially unreleased Gameboy Color version.

The wasps can't hurt the play character if he or she runs.

Out of the original monsters from the original version, the giant spiders are the only enemy to have a different name. They were called Web Spinners in the original, and now called Tarantulas in the remake.

In the cemetery directly behind the mansion (the one you enter through the painting in the main hall), all of the tombstones have ancient Greek texts on them. One word that is on every stone phonetically translates to 'Chapchom' in English, a reference to Capcom.

If the play character isn't equipped with a weapon, they can run slightly faster.

On January 20th, 2015, Resident Evil (2002) was remastered for the PlayStation 3, Xbox 360, PlayStation 4, Xbox One, and PC: Resident Evil HD Remaster (2015). These versions include 16:9 widescreen support, 5.1 surround sound, and improved character models, textures, and lightning. There's also an option to play with the original tank controls or new 2D controls. While the PS3 and X360 versions are 720p, the PS4 and Xbox One versions are 1080p.

The developers aimed to use the GameCube's graphical capabilities for "realism to a point", meaning discomfort without resorting to gross-out horror.  The Chimeras were originally suppose to grab the character up by the head from above and decapitate him or her and throw the body, while holding the head.  Zombie eyes were made milky white instead of dark to be more unsettling and make them feel more mindless. However, excessive use of blood, organs being exposed and dropping out of zombie bodies were rejected.

One early idea for this remake was to make the zombies invisible, but this was abandoned for the main game because it would have been too different from the original game; it was used as an unlockable game mode called Invisible Enemy instead. Another unlockable feature removed the interconnection between the item chests, meaning that items could no longer be retrieved from any chest, only the one they were originally placed in (this feature was considered for the original game but ultimately left out). Two different additions were made instead: dead zombies now resurrect again to become much stronger and faster Crimson Heads zombies; and an old deleted subplot has been reinstated, featuring the history of the Trevor family who were once held hostage at the mansion and experimented upon, which resulted in the nearly indestructible Lisa Trevor monster that haunts the mansion's grounds.

Art director Naoki Katakai had to repeatedly change his designs for the game's backgrounds and his lighting choices because they violated director Shinji Mikami's instructions that the surroundings should provoke fear rather than beauty.

Like the original, this remake technically has no in-game canon ending. Depending on the character selected at the beginning and certain choices made during the game, twelve different endings can be unlocked. Even though the remake contains several references to the later games in the series, it kept the multiple endings, none of which lead into the continuity established in those installments. It is generally believed that the unseen canon ending is a hybrid of Chris' and Jill's scenarios with their respective best possible endings, which has Chris, Jill, Rebecca and Barry all escaping in Brad's helicopter.

Hidden cutscene: There is a small room on the first floor of the mansion you can access from the main hall using the helmet key. Inside you will find a zombie, some herbs and a box containing the emblem key. If you kill the zombie, go back to the main hall and then come back to the room, a hunter will smash the door.

One can deduce who the traitor within S.T.A.R.S. Team Alpha is way before the final revelation, by listening to the shot that kills Enrico. Wesker's gun model makes a unique sound when fired, like no other STARS member's. It can be heard during the intro of the game when he shoots at the Cerberus, and in the residence when he shoots at the bees right before crossing paths with Chris or Jill.

If you play as Jill Valentine, there are a couple of hidden cutscenes at the very beginning of the game. Immediately go back to the main hall to trigger a cutscene with Wesker. Attempting to leave the dining room a second time will show Barry mocking Jill. Finally, after you talked with Barry in front of the fireplace, pass the door without opening it and the zombie will come into the dining room.  This hidden cutscene also happened in the original Resident Evil 1996 game.

When you come back to the mansion after getting the helmet key, hunters have spread around the place. There are three doors that they can break permanently on the first floor, making trips between rooms quicker. The most convenient is located in the area where you encountered the first zombie of the game. A hunter smashes the door leading to the L-shaped corridor with the greenhouse and the tiger statue. But it only happens if you go to the kitchen and then come back to the corridor.

The first boss fight with Yawn, the big snake, can be skipped. There is no need to fight him, grabbing the mask lying in the room and leaving is all that is necessary to proceed in the game; upon returning, the snake will have left as well. Yawn only needs to be defeated in the second fight.

In Chris' scenario, saving Richard from being poisoned or not has significant influence on the rest of the game. If you retrieve the serum before he dies, he will immediately give you his radio; Rebecca will be with him in the drug room for a while where she can treat wounds; if you are poisoned during the first fight with the big snake, Rebecca will get the serum for Chris as a playable character; Chris can collect Richard's assault shotgun in the Aqua Ring later; and finally, the Plant 42 boss fight will just feature Chris. If you fail to save Richard in time, Rebecca is not available in the drug room to treat any wounds; Chris will have to get the serum himself; Richard's assault rifle will not be available in the game; and you won't get Richard's radio until after the fight with Plant 42. The biggest change is that an additional cut-scene and side-quest are unlocked: at the start of the fight with Plant 42, it immediately grabs and immobilizes Chris. Rebecca will answer his calls for help, and Chris tells her to make a compound in the nearby lab that is toxic to the plant. Rebecca creates the compound and releases it next to the plant's roots, causing it to temporarily wither away and release Chris.

Mistakes

While in the main mansion, a storm can be heard and seen with rain and thunder.  However, whenever you're outside the mansion, the storm isn't happening.

If you play as Chris and put away his combat knife, it's still seen in the sheath strapped to his back.

When Barry rescues Jill from the ceiling trap, he shoots the handle on the door, and pulls it open towards him. However, considering that Barry is on the outside of the room, the door should only be able to move inward, not outward. Thus, considering how low the ceiling had begun to come down, covering part of the door, Jill would not have survived.

When Barry rescues Jill from the ceiling death trap, the ceiling is shown significantly higher over the door during the cut scene whereas seconds ago during game play, the door can be shown overlapping the door molding.

During the cutscene of Jill and Barry investigating the gunshot, Barry and Jill open the door and enter the dining room twice between two camera shots.

Right after the battle with the giant plant and you receive the helmet key, upon leaving the gallery Wesker appears and fires down the hallway three times. During the cut scene the hallways he fired down is shown to be empty with absolutely nothing down it. After the cut scene ends, three dead wasps suddenly appear in the hallway.

Every time a player character pushes a tall object, their hands push against the object with their hands/arms flat against it, despite the fact many such objects include suits of armor and intricate statues.

When you find Richard, he says that he was bitten by the giant snake. In the next corridor, you can even see his bloody finger prints on the wall next to the attic door. The attic is the place where you meet and fight the giant snake for the first time. Everything seems to indicate that Richard was attacked inside that room. Yet, you need to find the shield key to get inside. There is no way Richard could have entered the attic and get bitten as the door was locked.

In both endings, Chris and Jill are locked in a cell by Wesker. After they are rescued they each have their guns back. In Chris's scenario, Jill's gun is found in the mansion hallway. How did she get her gun back? There is also no chance Chris would have had his gun while locked up either.

When you play as Chris and fight Lisa along with Wesker, if Lisa should knock Wesker off and falls to his death, the games ending does not change, and both Chris and Wesker acts as if the event never happens.

There is a secret passage to the caves in the courtyard garden that cannot be accessed because there is a waterfall over it. Entering the caves involves diverting the water. However, getting wet should not deter the playable character from entering, especially since there is a whole section later that takes place inside a flooded shark tank. And even so, there are plenty of objects around that could be used as a make-shift umbrella.

In most of the endings, the self-destruct alarm goes off, and the PA system announces that all locks have been released. Even though the alarm and warning can be heard throughout the entire complex, the non-player character remains quietly inside the brig without attempting to open the unlocked cell door, unless the player character comes to get him or her.