A crowd of 10,000 people packed into the arena for an energized speech from the president.
The president spent the bulk of his time on positive notes about his agenda on issues like the environment, the economy, and women's health.
He did shoot back at Gov. Mitt Romney, who has been attacking the president's business sense.
"Now in the closing weeks of this campaign, Governor Romney is using all his talents as a salesman to dress up the very same policies that failed our country so badly," the president told the crowd. "The very same policies we've been cleaning up after these past four years. And he's offering them up as change. He's saying he's the candidate of change."
That drew boos from the crowd, which loudly supported the president.
At one point, Mister Obama rattled off a list of things the crowd didn't like about Romney, closing each sentence with "that's not change!" The crowd shouted back, "chump change!"
The president will return to Colorado for a rally in Aurora on Sunday night. He'll spend the weekend on Air Force One hopping between swing states, holding four events per day.
Both presidential campaigns are holding events in friendly areas when they visit Colorado, hoping to energize die-hard supporters to help spread the message.
As President Obama put it:
"That's why I need you to knock on some more doors! That's why I need you to make some phone calls! And if you turn out for me if you vote for me we'll win Colorado again! We'll win this election! We'll finish what we started. We'll keep moving forward!"
The campaigns are also hoping to get those votes in as soon as possible, highlighting the fact that Friday is the last day of in-person early voting in Colorado.