According to the official novelization Alice intended to dock the Arcadia ship in the nearest island, Katalina. She believed it would be a safe place with few undead creatures. The trip was never realized because of the attack. The novelization clarifies that during the gunfire Alice lost the Redfields from her eyesight and never knew what happened to them.
During the fight between Alice and the Tokyo zombies in the well lit, white hallway, Alice shoots and smashes the zombies, with blood shown coming from the impacts. However no blood ever appears on the white walls until the end, when only pools can be seen on the floor.
In the Moscow car chase a Las Plagas zombie is shooting at the heroes car with a DShK 12.7mm heavy machine gun. The bullets bounce off the car's trunk, while in reality they would go through killing the passengers.
When the system has to reboot, a drawer opens revealing Alice's clothing for the rest of the film. When Alice walks into the hallway her shoes are a high wedge heel, while later in the film during combat scenes, Alice's heels change from high wedges to low wedged heels.
Albert Wesker: The Red Queen is determined to destroy all life on earth. This is the last that remain of us, of the human race. It seems we're bonded against a common foe. This is why we needed you back. The ultimate weapon. This is humanity's last stand. The beginning of the end.
The following FAQ entries may contain spoilers. Only the biggest ones (if any) will be covered with spoiler tags. Spoiler tags have been used sparingly in order to make the page more readable.
Are there tributes to other movies in this story?
It appears that there are four homages: 1) the simulated U.S. neighborhood scene from Dawn of the Dead (2004), 2) Alice and Becky hiding in the house's bedroom closet from Halloween (1978), 3) Alice rides the industrial elevator up to rescue Becky as in Aliens (1986), and 4) Leon looking through binoculars for a way into a facility that looks very similar to the shield generators in Star Wars: Episode V - The Empire Strikes Back (1980).
Is there a scene during or after the credits?
No, after the credits start rolling, the movie is over.