--minify is still being improved and is not complete yet. As well, you need to say what libs you included. If you import "HTML" it is basically like including jquery.
EDIT: Well, technically, Dart is actually designed to be interpreted (or JIT compiled, or what have you) by the Dart VM, so calling it a "compiled language" was incorrect on my part. However, dart2js is a compiler, so, it should be doing compiler-y shit.