This is brilliant.
We here know that video games are a developing medium of art. Almost all art, Shakespeare, Orwell, Van Gogh, Kubrick, Mozart, and the like, are developed as a means to entertain and emotionally enrich. They serve no practical purpose, yet we are required to study them. Ergo, adding in the works of Valve, Team Ico, or Tim Schafer is no different.
If a person doesn't play video games, and is required to play Portal, it is no different than a person who doesn't often read being required to read Hamlet, or a person who rarely listens to music being required to analyze Bach. Learning the controls and solving the puzzles and learning to appreciate them is the same type of difficulty as learning to fully understand Shakespeare's writings. Once you've gained to ability to understand it, you start to appreciate its beauty. It helps that Portal is filled to the brim with artistic merit, is short, is cheap, and isn't very hard. A newbie getting into Portal will be the same as someone reading 1984. I'm not saying that Portal and 1984 have the same merit artistically, but that's because writing has had millenia to develop while video games are just getting started.
This is wonderful, and I applaud you. Not because "I wish I had a teacher who'd give me video games as homework" but because you're bringing new people into appreciating the brilliance of the art of a new medium.