This is a first attempt at a review statement for publications that are largely simulation based, but haven't made an adequate attempt at making the results reproducible.
The authors of the paper should be aware of the Science Code Manifesto, see http://sciencecodemanifesto.org/ and http://sciencecodemanifesto.org/discussion. Although XXX is an open source code, the authors should do more to enable readers to reproduce the results in the paper. Specifically,