Basics
First things first. There is a choice between Easy and Hard gameplay on the startup screen. There are several basic differences between the modes. In Easy mode, weapons come early and plentiful. You get an infinite supply of Ink Ribbon, so saving progress is simple (as long as you can make it to a Safe Room). The beasties are a bit easier to kill, and easier to dodge as well.
In the Hard Mode, you start with little more than a handgun and a smile. Items are not as plentiful, baddies are tougher to kill. There are fewer Inventory slots at the beginning of the game (although Carlos evens things up later, giving Jill a fanny pack as part of an event). Ammunition is also harder to come by.
The advantage of the Hard mode, outside of bragging rights, is the ability to gain special weapon pieces every time you fight and beat the Nemesis. These weapons cannot be gained any other way, and cannot be found in Easy Mode. You will also receive a ranking at the end of the game, and be privy to several character epilogues. Winning in Hard mode unlocks anywhere from 0-5 costumes. In Easy mode, only two will be awarded.
Gameplay apes the other RE games for the most part, but this one incorporates several new features, including an enemy dodging system that is a real help. Jill Valentine is a nimble little sprite, and she's given plenty of opportunity to show off her feistiness.
New-fangled dodging is achieved by pressing R the moment before an enemy attacks (if you do not have your weapon drawn). If you already have your weapon in the ready position, hitting A right as the enemy attacks will either dodge or knock the creature back, and Jill will be free to attack. In Easy Mode, the dodge is easier to trigger than in Hard Mode.
Another new and useful feature is the quick turn. This comes in handy in evasive endeavors, especially when fleeing the Nemesis. It's also helpful when enemies are closing on both sides. To execute the move, use the C-Stick.
Fight or flee? If you have a coward complex, get over it! There are plenty of times you will need to (in the immortal words of Monty Python) "Run away!" Running is accomplished by pressing B.
Pushing R draws Jill's weapon. Pushing A while holding either button will fire that weapon. Once pressing an R button, you can aim higher or lower using the directional buttons or left analog stick. Pushing L changes targets.
Some objects can be modified or climbed on to. To push a movable object, simply stand behind it and hit the up directional button. To get on an object, face the object and press A. To get off of an object, go to the edge and press A.
To climb or descend stairs, press up or down on your directional pad when you are facing them.
The circle button accesses Jill's current Inventory list: the items she carries on her person, ready for use. On this screen, Jill can mix ammo and Herbs with the Combine feature, learn more about an item by selecting Examine, or Equip a weapon. Jill also stores all the information she collects here, and it can be accessed by selecting the File feature.
Pressing the Z button will bring up the current area map. While in the map display, pushing Select will access other area maps (if available). A will zoom out for a better view of the big picture. Yellow indicates an unlocked door, red means locked.
During certain points of the game, Jill will be faced with a new feature called a "Live Selection." Choosing different options can radically affect the storyline for significant portions of the game. However, the areas will have to be defeated in order. This guide explores all options. Look for the Live Selection choice, then follow the (A) or (B) sections to determine the action required by selecting a specific option.