It actually seems like a really cool idea as a trainer for "non-UI-oriented" developers (that end up building UI anyway) -- minus all the subjective and dark pattern stuff.
Early in my career I worked with a really great graphic designer. Up to that point, I thought I was "decent" at doing UIs, as I was proficient in the technology (HTML/CSS), and could take a sketch/mockup/photoshop/whatever and turn it into something usable. We were basically building custom templates that worked on top of a custom CMS/shopping engine (pre-Wordpress/etc), usually matching some existing customer branding, so it wasn't exactly 1:1 from design to implementation.
What consistently amazed me was that then the graphic designer would take what I did -- even just doing minimal modifications like adjusting spacing/sizing/color -- and make it look 10x better. I quickly learned that my design talent was severely lacking, and that Photoshop/HTML/CSS/etc skills are totally independent from UX/design skills.
I still think there's lots of programmers that haven't experienced this type of thing and believe being good with the tools == being good at design. Systems like Bootstrap make things a bit more interesting, because it becomes easier to fall into the pit of success, but it doesn't substitute.
A good "game" like this seems like it would help to break the mindset of some of these programmers because fundamentally once you start recognizing things like mixed icon styles, misaligned elements, or inconsistent font styles, you really can't un-see it.