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 without saving.
Finish the game in Invisible Enemy mode.
Obtain all costumes.
Finish the game in Real Survival mode.
Finish the game without saving anyone using Chris.
Visit all places on all maps.
Obtain all weapons.
Finish the game on Normal difficulty or higher.
Finish the game on Hard difficulty.
Finish the game with Jill and Chris.
Finish the game in three hours.
Finish the game in five hours.
Finish the game on Easy difficulty or higher.
Finish the game saving Rebecca and Jill using Chris.
Finish the game using Chris.
Save Jill from confinement using Chris.
Finish the game without saving anyone using Jill.
Save Chris using Rebecca.
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.
Finish the game on Very Easy difficulty or higher.
Finish the game using only your knife.
Finish the game saving Chris and Barry using Jill.
Finish the game 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.
Defeat a Hunter.
Obtain the Helmet Key using Jill.
Defeat mother Neptune.
Defeat a Crimson Head prototype1 using Jill.
Survive your first encounter with Yawn.
Burn up two zombies at the same time with the lighter.
Save Richard with a serum.
Defeat a Crimson Head.
Save Jill using Barry.
Burn up a zombie.
Die for the first time.
Defeat a zombie.