Depends on what the teacher thinks about. People like to point out "either all games are art or none" but there are video games that are just games, not art. Art is expressing something, is created through creational (doh) processes etc.
Graphics, music and stories are, of course, art (even if they suck in your opinion because quality/taste doesn't equal art) but games that are just a digital GAME are not art. Even if Tetris has graphics and sound, it's just a puzzle you could play with real blocks on a table, maybe some lights and sounds in them. It had a huge cultural impact but that's not really what defines art.
You never know what that teacher thought about when he said that - if they thought about popular games, they might just be worried about their views.







