Turbulence in thin layer constitutes a prototype model of a flow that is able to cascade energy to both large and small scales. Its simplicity allows for an extensive investigation for different layer thickness from thick layers where all energy cascades forward to thin layers that all energy cascades inversely. In this talk I will review some recent results that demonstrate a variety of new phenomena that appear as the layer thickness is varied that include : split cascades, condensate formation, on-off intermittency, super-critical and sub-critical transitions. I will try to describe our present state of understanding of these phenomena and the many questions that are left open.
