Avoid Fighting
When attempting to finish the game in under five hours, avoid fighting whenever possible. For example, many of the zombies in the game do not have to be defeated; it is possible to run past them, thus saving large amounts of time. In addition, it is possible to skip a large majority of the Nemesis fights. When Nemesis appears, run for the nearest exit rather than engaging him.
Grab the Powerful Weapons and Use Them
There are times in "Resident Evil 3" when fighting is unavoidable, whether it is enemies blocking your path or a boss battle you cannot escape from. In these instances, use your most powerful weapons to quickly dispatch your foes. Weapons such as the shotgun or grenade launcher are some of the most powerful in the game. Ideally, avoid using weak weapons that require a large amount of time to defeat an enemy, such as the knife or the pistol.
Knowing the Layout of the Game
When attempting an under five hour run, it is vital that you are familiar with the layout of the game. Knowing the quickest routes to your objective, knowing the location of items required for progression and knowing how to solve the puzzles in the game allow you to save time. Reading game guides or playing through the game before attempting an under five hour run allows you to familiarize yourself with what to expect. However, also keep in mind that time spent on the inventory screen is added to your total.
Using a Completed Save
If you have already beaten the game a few times, you can use the unlocked rewards to help you finish the game quicker. For example, beating Nemesis in hard mode rewards you with powerful weapons and unlimited ammunition; these carry over to your next game when you load your completed save. You must defeat Nemesis on hard mode a total of seven times to unlock all of the bonuses.
Rewards for Completing the Game in Five Hours
When the game is completed in under five hours and you receive an A or S ranking upon finishing the game, various costumes are unlocked for your character to wear. These costumes are for cosmetic purposes only and do not change anything about the game. The three costumes available when you receive an A ranking include the disco costume, the police miniskirt and the biker costume.