Here is the full list of all 44 Resident Evil achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Finish the game in Real Survival mode.
Finish the game on Hard difficulty.
Finish the game in Invisible Enemy mode.
Obtain all weapons.
Obtain all costumes.
Finish the game in three hours.
Finish the game in five hours.
Finish the game using only your knife.
Finish the game without saving.
Visit all places on all maps.
Finish the game on Normal difficulty or higher.
Finish the game without saving anyone using Chris.
Finish the game with Jill and Chris.
Finish the game saving Rebecca and Jill using Chris.
Finish the game using Chris.
Save Jill from confinement using Chris.
Defeat Lisa Trevor using Chris.
Save Rebecca from a Hunter.
Obtain the "Last Book Vol. 2" using Chris.
Defeat Plant 42 using Chris.
Obtain the Stone & Metal Object using Chris.
Save Chris using Rebecca.
Save Jill using Barry.
Finish the game without saving anyone using Jill.
Finish the game on Easy difficulty or higher.
Finish the game on Very Easy difficulty or higher.
Finish the game using Jill.
Finish the game saving Chris and Barry using Jill.
Save Chris from confinement using Jill.
Break into the laboratory using Jill.
Save Barry from Lisa Trevor.
Defeat Black Tiger.
Defeat Yawn using Jill.
Burn up two zombies at the same time with the lighter.
Defeat a Hunter.
Obtain the Helmet Key using Jill.
Defeat mother Neptune.
Burn up a zombie.
Defeat a Crimson Head prototype1 using Jill.
Survive your first encounter with Yawn.
Save Richard with a serum.
Defeat a Crimson Head.
Die for the first time.
Defeat a zombie.