I don't want to sound harsh, but you really should have put more effort/time on the graphics or at least hired someone that would. We are not "This game's graphics rocks, so that's an awesam game, lol" guys, but do you really expect the players to pay for a game with backgrounds consisting of irrelevant layers? It takes hours, days to complete a background of an adventure game, no matter commercial or freeware.
And a "free demo"?
There are better ways to gain money.
And a "free demo"?
There are better ways to gain money.