I consider something art if it's meant to make you feel a certain emotion. How good it is as an art thus being based on how many people it actually inspires the correct emotions in, like something funny actually being funny instead of just offputting or boring.

So games CAN be art but not all games are art. ET on Atari? Not art.

Skyrim? Visually appealing and the setting could be considered an art piece but the game itself lacks any emotional depth so not art to me, just overly pretty for no reason.

Mother 3, art, and good art at that.