Plaid Cymru leader Ieuan Wyn Jones has urged his party to adopt attractive, radical and practical policies before the Welsh assembly election next May.
Mr Jones said Plaid could take the lead in 'rebuilding trust' in politics
In his annual conference speech in Swansea, he said "the time has come" for his party to be in government.
Mr Jones said it would be a challenge to convince voters the party is the only alternative to Labour.
"We need a fresh start for Wales and inspire our people that things can be different on their doorsteps," he said.
Mr Jones also acknowledged it would be a "real challenge" to convince voters that the party is the only alternative to Labour.
He added: "If the people of Wales are going to take us seriously as a government, between now and next May we must set out an attractive, radical, practical and achievable political programme."
Mr Jones took to the stage at the Brangwyn Hall after the audience had been warmed up with two party political broadcasts in which the leader was sold to the electorate.
LEADER'S POLICY PLEDGES
A grant of up to £5,000 for first time buyers towards the cost of a house
Financial contribution to help students to pay off debts, if they work in Wales for five years
Ensure official status for the Welsh language
Establish language commissioner as an independent ambassador for Welsh
Universal and affordable childcare for all children up to the age of four
Invest in a "decent" road link between north and south Wales
Target of cutting energy consumption in homes by 10% over 10 years
It was a contrast to Plaid's troubles after the 2003 election when he resigned from the party's presidency after a poor assembly election result.
In a 35-minute speech followed by a five-minute ovation, he said Plaid faced a "huge challenge".
"If we're going to do things differently, we have to be attractive and radical as well as practical and be able to achieve our programme," he said.
"But it won't be an easy thing to achieve because people have had enough of politicians making big promises up to an election but breaking those once in power."
He said he was determined that Plaid took the lead in "rebuilding people's trust in the political system".
Referring to the problems of affordability of homes for young people, Mr Jones said: "This is a tragedy and we must do something about it."
Mr Jones also raised the issue of climate change and the need for "real progress" on energy consumption.
The party's policy pledges include measures to promote energy efficiency, with a 10% target set for reducing household emissions over the next 10 years.
There would also be financial assistance towards the costs of energy saving initiatives in older properties, while the party also wants powers to set additional energy-efficiency requirements in new homes, schools and hospitals in Wales.
Plaid also unveiled spending commitments that include help for first-time buyers and student-loan breaks for graduates.
Earlier, Plaid parliamentary leader Elfyn Llwyd received a standing ovation when he called for a "return to honest politics."
The Meirionnydd Nant Conwy MP blamed Labour for the people losing interest in politics.
He said the nominated House of Lords was "a nice little earner" for Tony Blair.
Mr Llwyd said Plaid could overtake Labour in Wales if it stuck to its tactic for next year's assembly elections - to fight grass-roots local campaigns in target constituencies.