Radix Remix Update
As noted in the user reviews, the update to v2.0 (a.k.a. "Radix Remix") introduces some radical changes to the game. According to the patch notes, "Version 2.0 includes:
new graphics, new and improved visual effects, new levels, better controls, improved physics, and 2 new weapon upgrades.". The files needed to upgrade both shareware and registered versions of "Radix" are available on its official website.