Centenary of Canberra executive director Jeremy Lasek confirmed One Big Day on Lake Burley Griffin cost the ACT government about $3 million - 10 per cent of the $30 million budget for the year-long centenary celebrations.

Members of the public who attended the lakeside celebrations on Monday have complained that there was not enough entertainment, especially for families, during the day and what was provided was too ''highbrow'', ''too arty'', ''elitist'', ''too spread out'' ''ho-hum'', ''smacked of school fetes'' and a ''mishmash''. Patrons said they spent ''a lot of time walking and waiting for buses'' and not much else.

Others have said they had a great time, and particularly loved the reformed Canberra bands and fireworks and that it made them proud to be Canberran.

An online poll by The Canberra Times of more than 2300 people revealed almost a third found One Big Day disappointing while 6 per cent thought it was perfect. Seventeen per cent thought it was ''OK but nothing special'' while another 17 per cent thought it was ''good'' but some things could be improved. the other respondents hadn't attended the event.

Centenary of Canberra creative director Robyn Archer said she believed the vast majority of the 150,000 people who attended the celebrations had a positive experience.

''I can't move anywhere in Canberra at the moment without people rushing up and saying 'That was the best day we've ever had','' she said.

Ms Archer said there had been a conscious decision not to have run-of-the-mill entertainment such as jumping castles and face painting.

''It was absolutely intentional,'' she said. ''We wanted to do something that was original and different and genuinely interactive.''

Ms Archer said she was finding it difficult to understand where the criticism was coming from. ''Because I walked the lake many times and of the 500 snaps I took, 350 are filled with kids having fun,'' she said.

''And everywhere I walked, there was stuff to do. Kids were doing chalk drawings, they were cacking themselves at the ants that Polyglot [Theatre] did, there was really nice interactive sports things everywhere I went. Maybe there was an expectation that it would be like every event always is.''

Ms Archer said other features such as the specially commissioned symphony all added to a day Canberra had not seen before. ''I think it will remain memorable,'' she said.

The day had been ''brilliantly organised'' from her perspective.

''One is always sad when someone comes to your party and doesn't have a good time, but when I look at the amount of work the team did, the conception over 2½ years and the way they've worked, I was very proud of the team,'' she said.

Mr Lasek said he believed One Big Day did live up to the hype of being the party of the century.

He said the celebration was ''mind-blowing'' and among the most ambitious events staged in Canberra.

''I think well over 90 per cent of the event ran like clockwork,'' he said.

''There were a few things that were annoying but I don't think they overshadowed the fact it was an amazing event.'' He said catering was one of the issues from which they had ''learnt lessons''.

Both Ms Archer and Mr Lasek said the message had been for patrons to study the program of events before arriving.

''We tried to let people know the scale, we tried to let people know the sort of activities, what was on and where, but we were also relying on them to visit the website, keep an eye on the local media, ask questions of the team. I think most people did,'' Mr Lasek said. ''But between the heat of the day, the size of the event and the fact it ran for 11 hours, you probably couldn't please everyone who just turned up expecting it to all unfold in their lap…

''People really needed to know in advance. Maybe we needed to get the message out even more strongly.''

Mr Lasek said some of the criticism had been ''self-perpetuating''.

''If the media's feeding a line to the public, they'll respond to that line.''

Ms Archer said she hoped a lasting legacy of the day would be greater use of the water of the lake.

''I would hope that one of the messages would be, 'Let's loosen up around the Parliamentary Triangle'. Let's try to make sure we're allowed to have water craft in the middle basin, it looks so beautiful.''

Whether future Canberra Days would be of a similar scale had yet to be decided: ''That's a question for government,'' Mr Lasek said.