If you bought the game and you haven't received the email for the purchase receipt before the price drop, then they should give it to you as free.
Maybe I'm the only one but I don't care if (for example) swordigo goes free a day after I bought it, because it's a great game with hours of fun and well worth $2. I don't even care that Sonic Jump goes free, although I paid $2 for it and it's an average game.
If when I bought the game it sucked, I'd be pissed that I wasted money, but trust me I don't regret any of it. So glad I could experience this and help the developer.
