Heyo!
Different stores have different refund policies. If you buy through Steam, the two hours & two weeks limits do apply. If you buy through us, we offer a 'no questions asked' refund if the request is received within 48 hours of the purchase being made, irrespective of playtime. Valve's policy will work better for those who want more real-world time to make the decision, but if you're interested in spending a weekend answering this question for yourself, you might want to give our store a try.
(Support for PayPal is temporarily disabiled; it will be back in the very near future.)