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Friday 12 January 2018 at 01:49
The tar wont work. You need to gzip it first, then rename it to its old name. Then it might work.
After further investigations it seems that the web server tells the browser to unpack that file. Better wait for tomorrow until they fix it. Or use wget or some other dumb tool to download.
Source: http://pinside.com/pinball/forum/topic/alien-pinball-official-game-thread/page/390#post-4171290