I will discuss our recent experiments on continuously driven box-trapped 2D Bose gases. We have observed first and second sound in a hydrodynamic 2D Bose gas, which is the first such observation in a BKT superfluid [1]. The measured speeds of the two sounds allow extraction of the superfluid density, which agrees with the expected universal jump at the BKT critical point. I will also discuss our new results on strongly driven 2D gases in which a direct turbulent cascade emerges.