I've used it a bit with love2d for game prototypes. I love it. It has my favorite syntax of probably any language. The community/ecosystem is certainly lacking but growing all the time. It still needs a bit of work to simplify debugging with some kind of sourcemap functionality. And it is extremely fun, especially in combination with love2d.

Ecosystem wise, it's the Lua ecosystem. Compatible, from both sides of the coin.

It's classes are fantastic when working with structures that lean that way, like in games. (I've used it a fair bit with Love2d.)

Comprehensions and stabby-procs are also something that are nice to have. Makes it easier in some cases. Just more consistent in others.