Victoria Police arrested dozens of people for a range of offences including assault, robbery and drugs as thousands crowded into Melbourne's CBD overnight on Saturday for White Night.

Despite the arrests, police say they were "very happy" with the behaviour of late night revellers at the festival. Given the number of punters, they said, there were only 31 arrests.

Among the many authorised light shows was a "renegade" projection over the facade at Flinders Street station.

An anti-Adani projection over Flinders Street station. Credit:Courtesy Twitter: @AudreyCooke77

Police did not confirm if they arrested the Anti-Adani protesters responsible. There was a group of eight involved in the protest and their projector was confiscated on the night.