Dart is surprisingly nice, considering how little I hear of it. I picked it up recently as a target for my hobby project (a Clojure interpreter). Dart's VS Code integration is phenomenal. Its VM is pretty efficient from a resource consumption perspective (especially compared to the JVM). It's worth a look, for anyone who hasn't bothered with it yet.

Dart as language is nice, but it compiles to unreadable, bugged pile of obfuscated JS code. I've written one application in Dart and now regret it.