About 1000 people attended Tuesday's march and rally staged by the right-wing Freedoms and Rights Coalition in Wellington.
The figure was well short of previous rallies and failed to live up to expectations after protest leaders organised travel convoys from the North and South Islands.
Organised by firebrand conservative Brian Tamaki, who has previously led rallies against gay rights, the campaign aired grievances towards the government's COVID-19 response.
A member of Mr Tamaki's fundamentalist church played the role of judge, putting the New Zealand government on trial for "crimes against humanity".
However, no government members turned up to be part of the spectacle, leaving Mr Tamaki disappointed.
"Is anybody coming out? Is any politician coming out to talk to the people?" he asked over a loudspeaker directed at Wellington's Beehive building.
"This is absolutely undemocratic. It is a snub in the face of the people of new Zealand."
Many in the crowd carried inflammatory signs as they marched through the city centre, including one which read 'Free NZ, Ditch the Bitch'.
One of the chants sung was "when I say 'Cindy', you say 'jail time'," referring to a diminutive of the prime minister's first name.
The mock trial heard speakers who told of business struggles and family separations due to COVID-19 lockdowns.
The crowd declared the government guilty by acclamation, but did not give a sentence, with Mr Tamaki saying "watch this space".
Ms Ardern said she did not see the rally but was pleased it ran without reports of violence.
"Our hope was that we would (have) on parliament grounds, a peaceful and lawful process. By all accounts, it appears to have been of that nature," she said.
Police ramped up preparations for the occasion, stationing dozens of officers around parliament and blockading nearby streets.
A similar summer event spiralled out of control and produced a 23-day occupation which ended in arson and violence.
Protesters set fire to a children's playground and threw paving stones at police during a harrowing showdown back in March.
More than 100 people were arrested on charges including arson, grievous bodily harm, inciting violence, theft, assault, trespass and obstruction.
Researchers warned dangerous individuals, including neo-Nazis, could have infiltrated Tuesday's rally.
Ms Ardern said she had no desire to block protests at the seat of New Zealand's democracy.
"(Protest) is part of who we are as a nation," she said.
"Parliament is working very hard to make sure that we're balancing our responsibilities in a democracy ... to welcome peaceful and lawful protest."
During his speech, Mr Tamaki announced the formation of a new political party which will attempt to win seats at next year's election.
Australian right-wing blogger Avi Yemini attempted to travel to Wellington for the rally but was blocked by Kiwi officials.
An Immigration NZ spokesman told AAP Mr Yemini was denied entry on character grounds due to a criminal conviction.
