I will present the first results of the AustraliaN GADGET-3 early Universe Simulations (ANGUS) project. The aim of this project is to run state-of-the-art cosmological hydrodynamical simulations with an improved version of GADGET-3, to better understand the interplay between galaxies and intergalactic medium at z>2. In particular, I will discuss the results of two papers where we explored the star formation rate function, the galaxy stellar mass function and the star formation rate-stellar mass relation of z ~ 4-7 galaxies.