G#: A modern .NET language with Go, Kotlin, and Swift ergonomics

While the language itself doesn't seem very interesting (which is perhaps the point). The idea of building a new language on top of the CLR runtime feels very wise. Instead of a new language suffering from a lack of ecosystem, you get everything else that's already built, even in other (CLR-based) languages. This does leave me wondering what the trade off is. Do you sacrifice any potential language features for CLR compatibility? Or provided you can get it compile, it will run?

Also, are there other language ecosystems with a similar capability?