I just did it... I got SNP. I live in Scotland and won't vote for them as i want another referendum like i want a hole in the head.
But independence aside, i do broadly have the same social democratic outlook (especially on nuclear weapons, university tuition fees) as the SNP, i just think independence at this moment is a spectacularly bad idea.
This shows the strengths and weaknesses of this kind of website: it makes it about policies, but doesn't 'weight' the policies for their importance to the party and their pitch for power. For example I doubt anyone voted BNP based primarily on their recycling policy.
This affects N.I. and Scotland disproportionately, where politics is fractured over a single issue. A Catholic Nationalist would probably find much to endorse in the DUP's policies, bar their policy on a united Ireland, which trumps almost every other issue.
Even so, most people casting a vote in the election know SNP favour Scottish Independence and that the DUP are a Unionist party and filter the results through that. After the SNP the website matched my views as being aligned to the Lib Dems, who I'd already decided I'll be forlornly voting for in June.