If this were somebody's toy or research language, I wouldn't be complaining, but when a language is clearly being marketed as something people would want to use in the real world, I expect it to be based on real evidence and real experience, not just somebody playing around.
It's human readable as far generated code goes. It's not always practical to read (specially with classes), but you can if you have to. It's one of the philosophies behind CoffeeScript. As you can see its translation of OOP is verbose too, but readable [1], and the verbosity of the generated code is balanced by the power added on the CoffeeScript side.
My point/question was: it doesn't add a runtime or new libraries/routines, you can read the generated code if something goes wrong, so why wouldn't it be ok to use in production?
"Nice" is relative, I think the site is a colorblind monstrosity (it actually looks better when I invert the colors!), but someone clearly put some effort into it, as well as the reference manual, and there is no indication given anywhere that it should be treated as anything other than a serious entry into the world of production programming languages.
On the contrary, at the very top of the page, albeit in extremely poor contrast, it says "A programmer friendly language". That certainly implies the author considers it to be good for something other than "playing with new syntax".
