Lily's Well is honestly one of the scariest games i've played in a while, though i am not much of a Horror-buff. Twi major downsides are that the game gets repetitive very quick, and the music does dig into your ears if you have the volume a tad too high (similar to Lavander Town in Pokémon Red). However the endings are all honestly terrifying, and the 'beast ending' (no spoilers) was one of the best set up scares i've seen.
Be aware that the game includes a lot of body horror, so if you are not comfertable with that this might not be a game for you. However this IS a Horror game so i suppose that might improve the experience, i'm not so sure.
EIther way i'd say it's a solid 7,5/10