"I voted for Andrew Cuomo because I believed that he was a real Democrat," Nixon said. "But since taking office, he has shown us his true colors."
Later, she said: "If Washington is a swamp, then Albany is a cesspool."
Nixon's speech Tuesday came less than 24 hours after she caused a stir by entering the governor's race by posting a campaign-launch video that quickly racked up nearly 2 million views on Twitter.
She delivered her speech Tuesday at the Bethesda Healing Center in Brooklyn, a church with a predominantly African-American congregation.
The choice of venue was not an accident for Nixon, a white woman who must make inroads with diverse communities in order to have a chance at unseating Cuomo.
Nor was her choice of transportation to get to the event: The aging, often-hobbled New York City subway system, the condition of which Nixon has pledged to make a centerpiece of her campaign.
Cuomo has significant oversight of the Metropolitan Transportation Authority, the entity that runs the subway system.
"I got here just in the nick of time," Nixon said to open her speech. "I allowed an hour and a half for what should have been a 30 minute ride. Cuomo's MTA."
Nixon criticized Cuomo for accepting money from big-moneyed interests, pledging her campaign will not take a "single dime" from corporations.
She knocked Cuomo for not doing more to unseat Republicans from the state Senate, the GOP's final hold on power in New York. And she criticized Cuomo for allowing the Senate GOP to draw its own district lines in 2012.
Cuomo, meanwhile, is in a strong position for re-election, with more than $30 million in his campaign account.
A Siena College poll released shortly before Nixon entered the race Monday showed Cuomo with support from 66% of enrolled Democrats in New York. Nixon picked up 19 percent.
Earlier this month, Cuomo said he was unconcerned with Nixon's celebrity status and the impact it could have on the primary race.
"Normally name recognition is relevant when it has some connection to the endeavor," Cuomo told reporters on a conference call prior to Nixon's announcement. "But if it's just about name recognition, then I'm hoping that Brad Pitt and Angelina Jolie and Billy Joel don't get into the race because if it's just about name recognition, that would really be a problem."