Zak McKracken: Between Time & Space is an unofficial sequel to Zak McKracken and the Alien Mindbenders, and has been in development for more than seven years. The game boasts over fifty locations, 3D models, high-quality backgrounds and professional voice work - but the drawbacks are that it's in German, and the download size is close to 2 GB in total. (source: ScummVM forums)

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Zak McKracken retrospective
Zak Fan Game Team storm LucasArts