Tuples, Pattern matching, Structural types, Implicits, Collections framework etc. etc.
One of the biggest advantages of Scala is the community. Java has a culture of excessive over-engineering, boilerplate and XML. The Scala community tends to think more in terms of a fresh start, rather than seeing themselves as a Java extension. The extreme resistance to change within the Java community and unwillingness to look beyond the only tool in their toolbox makes are also major issues. Every feature is unnecessary complexity and evil until it gets added to Java, and then suddenly the "evil" feature in C# or Scala is suddenly an amazing new "innovation".
One of the biggest advantages of Scala is the community. Java has a culture of excessive over-engineering, boilerplate and XML. The Scala community tends to think more in terms of a fresh start, rather than seeing themselves as a Java extension. The extreme resistance to change within the Java community and unwillingness to look beyond the only tool in their toolbox makes are also major issues. Every feature is unnecessary complexity and evil until it gets added to Java, and then suddenly the "evil" feature in C# or Scala is suddenly an amazing new "innovation".