Much like Resident Evil 2 (Remake), Resident Evil 4 (Remake) and its DLC Separate Ways features a number of changes that makes it a very different experience from the original Resident Evil 4 in both gameplay and story, while also expanding some of the key plot points questioned in the original RE4.
Story-Specific
Chapter 1
- When Leon arrives at the village with his two police escorts, one of them wanders into the forest to urinate and hears a noise from the nearby Hunter's Lodge, going to investigate. His absence after a while necessitates Leon to exit the vehicle and look for him. He finds the officer dead in the basement of a nearby lodge, but Ganados attack and capture the second officer that remained in the police SUV. This second officer is later tied to a post and set on fire in the village square. The first officer is later removed from the lodge basement, decapitated, and fed to Del Lago. Originally, both officers stayed in the car, which was pushed off a ledge by a nearby truck. Their fates are mostly unchanged after that, though the second officer is already burned to ash when Leon reaches him and the first officer is not decapitated before his body is fed to Del Lago.
- The remake keeps Leon's mission, finding the President's daughter, a secret from the police. In the original, Leon just straight-up tells them he is looking for the missing President's daughter, though the police's dialogue implies that they don't believe him.
- Leon's first call with Hunnigan in the original game is the first time they talked, introducing themselves cordially. In the remake, their first call suggests that Leon had already met Hunnigan prior to this mission. It also happens in the lodge, as opposed to on the trail leading to the village.
- Leon's mission begins at a different time of day; whereas the original had him arrive at the village in the day time and the rest of the game took place from the day time into the evening and then through the night, finally ending at sunrise the next day, the remake has him arrive at the village just as day breaks, he then is captured in the early morning and makes his way through the valley in the afternoon/early evening, arriving at the lake at dusk.
- The first Ganado Leon runs into is seemingly killed then and there, but comes back later to attack Leon and Luis when they are tied up together. In the remake, he is killed in a cutscene, but reanimates offscreen and attacks Leon again, but this time with the Plagas operating his central nervous system (showing off the new ability they have) in the basement of the house you met him in.
- A particular tearjerker example for many players was the fate of the dog caught in the Bear Trap early on in the game. In the original, you could rescue the dog along the way to the village after leaving the hunter's cabin, and to show its appreciation, it would show up later on during the boss fight against El Gigante. In this game, you also encounter a dog caught in a bear trap early on, only to realize - to many a player's horror - that it's already long dead and its carcass is being picked clean by a bunch of crows. This is subverted later on, when you realize the dead dog at the start is a different, dark-furred version, and the white-furred dog we all know and love is caught in a bear trap next to Mendez's house much later in the game. Once again, players have the option of getting the poor thing out of the trap, and much like the original, it'll show up to assist Leon against the first El Gigante.
- The boulder running quick time event portion of the area is replaced by Ganados blowing up a trap and causing a rock slide. Leon can avoid it with a button prompt or simply walk away from it when it detonates.
- The hammering noises that bring Leon to the cabin past the farm are not from Luis but instead a Ganado boarding up the basement where Luis is instead tied up in a sack. Likewise, the conversation between Luis and Leon goes differently this time around, where among other differences, Luis never makes any mention about being a cop.
- It is Bitores Mendez who injects the Plaga into Leon when he's first captured, instead of a random Iluminados cultist. He also does it immediately upon subduing Leon. His confrontation with Leon also goes slightly different, as since it's in a cramped dark tunnel, Leon is unable to do his awesome spinning round kick attempt, and instead simply points his gun at him.
Chapter 2
- Leon loses his weapons and gear when he is first captured, along with his jacket. He is able to recover his weapons fairly quickly, but the jacket is still lost for the duration of the first playthrough. (It is later unlocked for use throughout the entire game after the first playthrough is completed.) Originally, they left him with all his weapons and only took his jacket. Hilariously, Separate Ways reveals that the jacket was taken by a random Ganado in the abandoned factory, and retrieving it is a merchant request.
- The Commilos now are introduced much sooner, as a pack of them is released into the village on your second trek through it. This can actually even be prevented if you kill the Ganado before he releases them. Originally they first showed up after the battle with the Del Lago.
- Leon will now immediately check the church door as soon as he approaches it, whereas before he could try and walk by the building, only to get a scolding call from Hunnigan.
Chapter 3
- When Leon retrieves the Insignia Key from the Village Chief's Manor and returns to the village, Ganados detonate explosives in the bell tower and cause it to collapse, blocking off parts of the village and forcing Leon to use an underground passage or cut through one of the houses to get from one end of the village to the other.
- After defeating Del Lago, Leon passes out due to the Plagas infestation but does so in the boat instead of reaching the opposite shore and entering the cabin. Del Lago also does not drag him under when it is slain.
- Saddler makes his first appearance in the remake telepathically communicating to Leon due to his Plagas infection. He will not make an in-person appearance until near the end of the Island arc, compared to the original where he appears in the church and castle as well.
Chapter 4
- El Gigante was first brought out by a group of Ganados who quickly lose control of it and are promptly massacred before Leon's fight with the creature. Here, it is summoned by a red robed Zealot, making their first appearance much earlier in the game. Also, this time instead of the dog just disappearing as soon as the fight ends, it can be found relaxing off to the side of the entrance of the area.
Chapter 5
- Saddler does not make an appearance at the church altar when Ashley is first recovered, instead telepathically sending commands to his Ganados to recapture them.
- In keeping with the more serious tone of the remakes, the infamous "Ballistics" line from Luis is changed to Luis noting Leon has found his senorita. Ashley somewhat curtly notes that she has a name and introduces herself.
- In the original, the villa siege ends with the Ganados simply giving up and wandering off. In the remake, Ashley opens a door for Leon and Luis to escape, with Leon crushing a Ganado under a heavy gate in the process.
- The fight originally ended when a set number of enemies were defeated. Here, there are two distinct phases to the fight. In order to pass the first phase, Leon has to board up all three windows on the ground floor (this is optional and instead a certain number of enemies can be killed). The first set of boards are available at the beginning of the fight, but the other two must be obtained as drops after killing enough enemies. Once the windows are secure, the Ganados use ladders to enter the top of the house and the fight continues until a Brute Ganado breaks through. After he is killed, the fight ends.
- Luis confirms that Ashley and Leon are infected with Las Plagas immediately after the cabin fight, rather than in the castle in the original. He also establishes communications with them via Leon's earpiece.
Chapter 6
- The two possible routes to the castle entrance from the original (one housing an El Gigante and the other a multitude of Ganados and the Bella Sisters) is revised into one mandatory route through the Bella Sisters.
- In Separate Ways, it turns out that Ada fights the El Gigante that would have been encountered in the second route.
- Leon and Ashley don't ride a gondola to and from the abbatoir that the fight with Mendez happens in. Instead, Mendez appears soon after the encounter with the Bella Sisters mentioned above, starting a chase sequence that leads the duo there, and getting to the castle after the fight doesn't require any backtracking. The beginning of the chase sequence is also where Mendez twists the bars holding a gate shut to prevent Leon and Ashley from escaping, instead of doing it at the abbatoir to lock Leon in with him.
- Instead of the two of them, it is Ada who rides the gondola in Separate Ways but this section is at the Island, not the Village area.
- The usage of Mendez's false eye to open a retinal scanner to the castle entrance has been removed, as the presence of such a modern device in a rural isolated farming community made no sense. The eye is instead now just a sellable treasure.
- Unlike the original where Leon and Ashley themselves propped up the drawbridge to avoid the incoming Ganado mob, the remake has the drawbridge pull up the moment Leon and Ashley cross, trapping them and forcing them to head into the castle.
Chapter 7
- The Zealots in the castle now feature quite a few female cultists, though it's difficult to tell them apart from the male ones other than by their voices.
- Salazar, while still short, now has a more appropriate appearance in the remake of a severely-aged man despite being noted to still be young, compared to the original where he looked like a child. He is also dressed more like he's from the late 17th century, rather than the late 18th century.
- Ashley's first separation from Leon in the original was running in fear of her Plagas infection, only to run into a rather obvious trap that captures her. In the remake, Ashley became possessed due to Saddler's influence with her Plagas infection, causing her to pull herself away from Leon. Despite regaining her composure, she flees in shame and fear of harming Leon, locking herself in a room, though not trapped by any of Salazar's machinations.
Chapter 8
- The section between Ashley and Leon's first separation and their first reunion (consisting of the Novistador filled sewers, dozens of castle rooms, fights with the red "Leader" Zealots, the hedge maze, a meeting with Ada, Ashley's rescue and Ashley's No-Gear Level) is reworked into a detour through the Wine Cellar and Castle Battlements. Ada's meeting and a fight with a red Zealot are retained, while the hedge maze now occurs right after Ashley reunites with Leon.
- In addition, Los Iluminados never jams Leon's communications link with Hunnigan; instead, severe weather forces Leon and Ashley to take refuge in a castle. Communications later become spotty as Leon explores the castle, but jamming is never explicitly mentioned. Leon also never makes an attempt to reestablish communications.
- In the original, Ada barely even acknowledges Ashley's existence and the only time they are even in the same room is near the end when she distracts Saddler to while Leon rescues her. Here, Ada and Leon now have a conversation where Ada advises him to just ditch Ashley on account of her infection. Ashley herself will also talk to Ada briefly right before the latter tosses Leon the rocket launcher needed to defeat Saddler.
Chapter 9
- The section between Ashley's first reunion and her second separation is remixed into a level in the Grand Hall. Some of the castle content (e.g. room with an elevator pathway, chimera pieces) cut from the "first separation section" are remixed here, and Ashley's No-Gear Level now also takes place in this section.
- Rather than being abducted by a Novistador in the Novistador hive, Ashley is abducted by the Verdego in the Grand Hall after her No-Gear Level.
- Ashley's solo sequence in the remake has been adjusted from transiting from her trapped location to Leon into rescuing Leon from a trap.
- Prior to getting trapped, Leon and Ashley had to get the heads of a snake, lion and goat and fit them on the Chimera statue which said trap was then triggered by a Zealot, trapping Leon. These 3 heads are nods to the lion, snake and goat ornaments which, after setting the ornaments, Ashley gets trapped not long after running away from Leon in the original RE4.
- Leon was trapped in a cage shortly after entering the dining room, and fought a Zerg Rush of zealots and a Garrador. Here, the entire sequence is in a cut scene, with fewer zealots and no Garrador.
Chapter 10
- Novistadors now are not met until just before the ballroom (roughly equivalent to the Novistador hive from the original). Their first encounter in the original, the castle sewers, is transplanted to the Separate Ways campaign. The Novistador hive itself is also not seen in the Castle proper, and instead becomes a part of the mines.
- Saddler's distrust of Krauser is completely absent; in a Chapter 10 cutscene, he refers to him as his "trusted disciple" and sends him to retrieve Ashley from Salazar. It's also implied that Saddler is tolerant of Salazar but sees him as more of a useful pawn than a member of his inner circle.
Chapter 11
- Luis now accompanies Leon through the mines section under the castle (including the double Gigantes fight and the minecart ride), which took place after his death in the original game.
- The Plaga suppressant Luis gives Leon is now a pair of injectors instead of a pill bottle. Makes sense, as liquid medication kicks in faster than in pill form and an injection will target the parasite better.
- Krauser is now encountered towards the end of the mines section, instead of first appearing on the island. He is also the one to kill Luis, throwing a knife into his back.
- Krauser and Ada are both part of Wesker's organization in the original, with the former acting as their Double Agent in the Los Iluminados. There's even a scene in the original where Krauser doubts Ada's loyalty and warns her not to try anything funny. The remake changes it so that Krauser is now genuinely a member of the Los Iluminados, while Ada is now Wesker's sole agent in the village.
- Rather than Ada betraying Krauser and shooting his knife away to save Leon, Luis is now the one to do it in his dying breath.
Chapter 12
- The Ramon Salazar statue is still present, where in-game lore mentions that one of Salazar's ancestors went a bit crazy on spending the family fortune building elaborate traps all over the castle. While it doesn't chase Leon like it did in the original, he can get close enough and it will start spinning while spitting out flames (idea likely remixed from the "lava and fire spewing dragon head room" from the original). Players can shoot a canister on the back of its head to destroy it.
Chapter 14
- Ashley never operates a bulldozer and the entire sequence is instead combined with the "wrecking ball room"; here, she operates a tracked wrecking ball which Leon must defend. However, the wrecking ball itself is always stationary.
- Krauser's boss fight is no longer framed after obtaining 3 key items needed to progress past his level, despite the overall layout still being the same. He also assumes his transformed appearance in the area where the first key was in the original and forces a brief ambush segment where Leon must progress through a closed-off underground area while he attempts several sneak attacks. Krauser's final phase is also not fought on a time limit, in contrast to the original needing to be cleared within 2 minutes lest Leon is killed by the tower exploding.
- The backstory provided by Resident Evil: The Darkside Chronicles indicates that Operation Javier was the first time Leon and Krauser interacted with each other in the original canon. In the remake, as shown in the game's opening prologue, Krauser was Leon's instructor during his Training from Hell to become a government agent. Additionally, based on documents from Chapter 14, it's implied that Leon was not part of Operation Javier, as notes in the game state that the unit sent was not only wiped out with Krauser as the Sole Survivor, but also left for dead by the U.S. government. This contradicts its ending where Krauser, Leon, and Manuela were all evacuated by the U.S. government.
Chapter 15
- Rather than a random Iluminados taking down Leon's support chopper, Saddler now summons a swarm of Novistadors that attack the helicopter, causing it to lose control and crash.
- When Leon and Ashley reach Luis' machine to remove the Plaga, Leon in the original volunteers to go first to make sure the machine is safe for Ashley. However, in the remake, due to the advanced infection of the Plaga, Leon puts Ashley through the machine first to make sure she is cured in time.
Chapter 16
- Saddler's motivation is different in the remake. While both versions want to use Ashley as a means to infect her father, the U.S. President, their reasons differ. Originally, Saddler wanted to take control of the Government to take the country and its power. If that failed, he would destroy it with a Plagas plague, then pick up the pieces. In the remake, he is a Knight Templar who believes he will bring world peace by uniting the entire planet with the "glory" of the Plagas.
- Unlike the original where Saddler could be killed either by Leon’s repeated knifing and gunfire or by the rocket launcher provided by Ada, the remake adjusts the scenario with Saddler’s second transformation so that Leon must use a rocket launcher to expose Saddler’s body, after which he then uses the sharp end of Saddler's staff to stab and kill Saddler.
- For the island’s self-destruction sequence, it was originally triggered by Ada after she takes the Plaga sample from Leon and boards her helicopter. In the remake, Ada does not trigger the self-destruction, and the island simply starts blowing up momentarily after Leon kills Saddler. Separate Ways, however, reveals that Ada did trigger the self-destruct sequence, albeit via hacking under Wesker's orders and right before the fight with Saddler.
- After obtaining the Amber sample at the end of the game, Ada realizes Wesker wants to use the Plagas just like Saddler did. After witnessing the carnage firsthand, she hijacks the helicopter and has it go elsewhere.
- On the jet ski, Ashley no longer asks Leon if he wants to do some "overtime." Instead, she just offers to have her father put him on her security detail.
Gameplay-Specific
- To keep up with modern Resident Evil games, Leon can now move and shoot at the same time.
- The knife has undergone significant changes. It now has a durability meter and takes up a slot in the inventory as well as being upgradeable.
- Upgrading the capacity on a gun doesn't fill the magazine. You have to reload the gun yourself afterwards to make use of the increased capacity.
- New enemy types have been added, such as the brute Ganado with a bull's head, who can come with a hammer which resemble smaller versions of the Executioner Majini from Resident Evil 5. There is also a version with an automatic crossbow bolt gun on the island, who replaces the JJs/Gatling Men.
- Two additional automatic guns are available for Leon to use, the CQBR Assault Rifle and the LE 5 from RE3 and RE2 Remake respectively, compared to the original where the only automatic option was the TMP (not barring the bonus Chicago Typewriter). For Ashley, she uses a lantern instead of a flashlight during her playable segment that has an additional function other than lighting her way.
- Many weapons have had minor changes to give various benefits and trade-offs, especially in light of the laser-aiming module only mounting to certain weapons now. For instance, the Broken Butterfly and the Red 9, both known for having high damage per shot, now don't have reticles affording pin-point distant accuracy, allowing the Killer7 or other handguns to get an edge in that regards. Both the regular bolt-action rifle and the semi-auto rifle (now dubbed the Stingray) have an aim-down sight view with iron sights by default instead of having a built-in scope.
- Incendiary Grenades have been completely removed from the game, being replaced with "Heavy Grenades" which act just like regular Grenades but have more powerful explosions.
- Ashley overall in the game had multiple mechanic changes.
- Instead of a health system, Ashley now has an incapacitation stage if she takes a hit. She can still die if she takes another hit in this stage, but Leon can recover her from this stage by interacting with her.
- Instead of setting Ashley to follow or stay with Leon, the new control is maintaining a tight or loose formation with Leon, with tight being to stay behind Leon in fights and when running pass enemies, while loose is for her to keep her distance from Leon while he fights, including making space away from enemies to avoid getting captured easily.
- Although there are still some situations where Leon has to catch Ashley after a particularly long jump down ledges, Ashley now proactively uses ladders or even make small jumps so Leon doesn’t have to always catch her (and as a form of character development, in the last long drop down opportunity on the island, if Leon doesn’t catch her, Ashley will jump down by herself.)
- If Ashley gets caught in a bear trap, unlike the original where she would stay stuck (while slowly draining her health), Ashley in the remake would actually be able to free herself from the bear trap after enough time pass.
Separate Ways
- Arguably the biggest change in the Separate Ways DLC is that Ada becomes infected with a variant of Las Plagas, raising her own stakes in the conflict and requiring her to ensure Luis stays safe until he delivers the medicine and the amber.
- Most areas that were removed in Leon's campaign run in the remake are reinstated for Ada. This includes, but aren't limited to, the drill trap in the castle, the Novistador-filled underground waterway, the comms tower and the laser hallway.
- Ada now starts her campaign in the castle, and doesn't enter the village until Leon has left it.
- After encountering Mendez in the village and attempting to escape from him, Ada collapses from the strain of her infection acting up (instead of the rather nonsensical tranquilizer dart that came out of nowhere in the original game). And unlike the original game where she was then tied up and about to be ritually sacrificed by the villagers before she wakes up just in the nick of time, this time Wesker saved her from them and took her back to Mendez's house, which is where she awakens.
- Ada encounters the black-cloaked Verdugo at the beginning, named Pesanta according to the notes with the designation of "U-III," and who follows her throughout her campaign. She later has to confront him as a boss fight in an area similar to where Leon fought U-3
in the original game, to which Pesanta transforms into a version resembling the original U-3. Ada defeating Pesanta is what frees her from her parasite infection. Speaking of the final U-3 boss battle, the initial chase from the original through hanging container pieces is omitted. However, as a twist, when Ada "kills" U-3, U-3's tail is revealed to be sentient and begins the second state of the boss fight. - Wesker doesn't spend the entire story sitting in a control room. He actually shows up shortly into the scenario to rescue Ada from Mendez and his villagers and remains on-site for quite some time before departing shortly before the end to get back to his command center. It isn't quite clear why he's personally in the area until late in the last act when Ada finds out he's setting up explosives all over the island to destroy Los Illuminados's facilities (in the original game, it was not confirmed but implied that Krauser was the one who rigged the island to blow) and he also recovered Krauser's corpse. The end also shows Wesker's control room is actually in a repurposed cruise ship explaining how he is able to get to and from the area so quickly.
- Wesker no longer explicitly orders Ada to kill Leon if she encounters him, forcing her to avoid him as much as possible. Instead, Ada insists on letting Leon live so he can continue decimating Los Iluminados, which Wesker grudgingly agrees to.
- The incredibly over-the-top sequence in the original game where Ada destroys a battleship with a mounted turret is completely omitted and is replaced with an area called the "Defensive Line" where she has to get past three hardened pillboxes with heavy machine guns and a small army of Illuminados. The battleship is indirectly referenced in the note right before she picks up the special rocket launcher in the end where the designer states the warhead is capable of even penetrating battleship armor.
- Ada does not get to fight Krauser in this one. In fact, they never even interact, mainly because he doesn't work for Wesker this time.
- A new monster is introduced in Ada's campaign, Martinico on the island. Martinico helps serve two purposes for Ada's story, one is to show what exactly the "Amber" can do to enhance the Las Plagas power, and second to put additional context to the laser hallway on the island, which has been given an additional purpose as a security measure to prevent Martinico from breaking out.
