Developer Aspyr's remake of BioWare's 2003 Star Wars RPG Knights of the Old Republic has had its hand lobbed off by daddy studio heads after a "vertical slice" of the game gone awry:
On June 30, Aspyr finalized a demo of the game, known as a vertical slice, to show to production partners Lucasfilm Ltd. LLC and Sony Group Corp. [...] The following week, the company fired design director Brad Prince and art director Jason Minor.
More on that in the Bloomberg article, which paints a lot of doom and gloom for what I'd have imagined would be a relatively straightforward excursion. Such is the way with Star Wars, though.
Wow. How difficult is it to take a brilliant game design and make it look prettier? :-/
The problem is that "make it prettier" was apparently not all they wanted to do. From what I read, they were using a different engine and revamping the combat from d20 to something more action-RPGy.
With how the original game works, how a lot of the original game is build on top of each other, that can quickly spiral out into replacing everything. This is just a guess, but I can totally see them getting overwhelmed by seeing the whole net getting undone after pulling on one string.
All the game scripts are pretty tied to how the original engine, the conversations and area objects call game scripts. The items are bound to the ruleset and combat system, as are the models. The original data files that can be reused get less and less as you accommodate the changes. Rebuilding all that would essentially mean developing a whole new modern style game.
More realistical would have been doing what the Enhanced Edition of Neverwinter Nights did: keep the original engine and just replace assets piece by piece. You wouldn't be able to fundamentally change the gameplay, though.