It appears that developing The Witcher 3 at CD Projekt Red was all about fun.

It appears that developing The Witcher 3 at CD Projekt Red was all about fun. For example, the team used Geralt’s skidding mechanic to turn the main hero into a snowboarder with a hat, a pair of goggles and a board under his feet.

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There was one point when we were like let’s implement this whole skidding thing that Geralt does when he’s on the slope. And people had just too much fun [so] they decided to try this on this mountain and fix Geralt’s texture so he looks like a snowboarder and they just let him go and made him skid [down].

Len de Gracia 

What more, there was a bug with all undone (ctrl-z) content being dumped at a secret 0.0 coordinate in the game. Then the team finally found the mistake.