You couldn't do that, because it would be illegal. You would be held accountable for your actions, and it would ruin your (fairly significant) reputation in any case.
Kickstarter exists for people who would never be able to get the product created, otherwise. Backers know that it's a gamble, because they might not enjoy the end product, but they think it's worth helping someone realize a dream. If a backer only cared about buying the product, they could just wait until it was released normally, and buy it at full price (and return it if they didn't like it).
It wouldn't make sense to offer a refund on the Kickstarter, because after the product has been created, that money is gone - there's no money left with which to provide a refund. A well-managed campaign will make exactly enough money to offset the costs required to produce the game and all of the backer rewards. Even then, it's not uncommon for a project to run out of money before everything is done. If someone expected to have money left over after the project, and could afford to give a refund to anyone who asked, then that would be a huge red flag that they're asking for too much money.