I posted the following on the Card Kingdom development blog.
Object serialization and audio have both been in the new iteration of engine from the beginning, but had little to no work done on them since other systems needed more focus during the initial stages of development. Now that these systems are in a state of equilibrium, serialization and audio can be worked on.
Our serialization model is inspired by Java’s (without the automatic reflection of object variables). Objects that want to be serialized extend the ISerializable interface.