I kinda posted this by accident on the actual comment thing on the game page, sorry but yeah as the title said, I don't know why but other people seem to have been able to unzip it fine (noted by the ratings) I don't know why it didn't work for me... anyone else with the same problem? (I didn't see any forum specifically for ROm bugs, I hope this is the right place)
Because sometimes when you download part of the data isn't sent so it gets corrupted, only thing to do is re-download. It won't cost you points so long as you start the new download within 24 hours of your initial download. If your download is cut off prematurely then you can use a download manager to resume it.