I tried the Steam version, but it should run just as well if you run the original windows version from the game's web site.
It's an automatic Silver, but I bet it's really Gold, so that's what I'm giving it.
I completed the first stage with no problems, the menus work well, the game saves properly. It's great.
Edit: I completed the game (although not 100%) and it certainly would deserve the Gold, were it not for the fact that setting the game to fullscreen made my desktop unusable. 😥
It's a Flash game, so if anybody knows of a way to make CXG run fullscreen Flash apps properly, let me know!
Edit 2: In a netbook, the Time Trials (with the extra GUI they entail) might be too CPU intensive to be playable.