Due to changes in Scala macros between 2.10.x and 2.11, support for building against 2.10.x has been dropped. The current incarnation should be compatible with 2.12, though I have not yet tested this. If the community feels 2.10.x support needs to be reintroduced, I can do so.
At the moment, [ReactiveMongo Criteria](https://github.com/osxhacker/ReactiveMongo-Criteria) is not available on Maven Central and must be built/published locally. This is a high priority item and one I hope to have resolved in the near future.