Yes, FACES is a Scrabble word!

Letter values in Scrabble US: F 4, A 1, C 3, E 1, S 1.

Is it a valid word?

FACES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

the front of the human head from the forehead to the chin and ear to ear
the feelings expressed on a person's face
the general outward appearance of something
the striking or working surface of an implement
a part of a person that is used to refer to a person
a surface forming part of the outside of an object
the part of an animal corresponding to the human face
the side upon which the use of a thing depends (usually the most prominent surface of an object)
a contorted facial expression
a specific size and style of type within a type family
status in the eyes of others
impudent aggressiveness
a vertical surface of a building or cliff

deal with (something unpleasant) head on
oppose, as in hostility or a competition
be oriented in a certain direction, often with respect to another reference point; be opposite to
be opposite
turn so as to face; turn the face in a certain direction
present somebody with something, usually to accuse or criticize
turn so as to expose the face
line the edge (of a garment) with a different material
cover the front or surface of

Also: human face, facial expression, face up.