The thecubeescape.zip file you have requested: Maps Levels Missions / Single Player / The Cube - Escape - 18.9mb is not available. Perhaps try browsing all files for the game Portal and upload any files you want to share or are missing. This is the only information we could locate:
Inspired by the movie with the same name, maybe frustratingly difficult at the beginning because of the high mortality rate, but then again the movie wasn't about a walk in the park either. Took me about 3 months to create so I hope you enjoy it.