Youngster Arielle said it was exciting to get the chance to cut the ribbon with the Mayor and to be one of the first to play on the new equipment.
"I think the best thing is the big slide as it was fun, and I also like all the colours," she said.
Mr Crosby said he wanted to thank all those people involved with the project, which incorporated a number of features young people had asked for during a council-led public feedback survey.
Saturday was an exciting day for the many young children, all keen to play on the creation, with a mad dash once he and Arielle cut the ribbon, he said.
"There was no stopping them. It reminded me of the old-fashioned bull rush, it was great."
Mr Crosby said the playground was stage three of a multi-staged $5.5 million programme planned over 10 years to bring more people back to the waterfront, he said.
"The playground was to give young people an opportunity to enjoy the waterfront. When you looked at the CBD there has been very little for young people to do, and this is something I have been quite keen to change over many years," he said.
"I'm sure the playground will help attract more young people to come down and enjoy what the waterfront has to offer."