The SNP gained nearly twice the seats they were entitled to. Meanwhile, the Greens, LibDems, and (especially) UKIP were robbed. 12.6% of the vote and one seat out of 650? That's not democracy - its a scam! And then they wonder why people don't vote in the UK. When your vote doesn't even count, why would you?
(Under proportional representation the UK would be looking at a tory-UKIP government right now. Which isn't good, but it would at least be what people voted for. Unfortunately I just can't see the UK moving towards electoral reform. While the need for it is obvious, the political establishment benefits too much from disproportionality - it keeps the "right" people in power, while keeping out anyone who wants real change. Scotland has proportional representation, and just look at what happens there...)
As for how the results differed from the polls, I think the tories' Scotsphobic campaign worked at the last minute. They won it by inciting fear and loathing of the Scots in England. But unlike Jim Bolger, they don't seem to have considered that they'd need to govern the country in the morning. Now they're in power, their Little Englander voters will rightly expect them to deliver on their implied promise to put those uppity Scots back in their place as a subject people. But if they try to, the result will be another independence referendum - and this one will be successful. They may face that anyway as a result of their promised EU referendum. Which is a tad careless from people who profess to stand for "the union".
As for UK Labour, they're displaying the same sort of ugly entitlement that we've grown to expect from our local version, blaming voters for deciding that other parties better represent their interests. Which will just turn voters off even more. Like NZ Labour, they're a dying party - and with a leadership cadre of second-rate apparatchiks, they're unlikely to be able to reverse the decline. But with no real replacement in the wings, their failure will result in decades more of tory government.