Really, Terraria is a great game. If you have a pirated copy, please consider buying the game and supporting the developers. If you don't have access to a debit card, go to Walgreens and pick one up that's prepaid. That's $15. There are zero (read: 0) people on this planet with access to a computer, electricity, and Internet access who are unable to obtain fifteen freaking dollars. There is no excuse. If you are just testing the game out, you must like it, given the fact that you are at this website. Go buy it.
If not for the legal reasons, then buy it for the moral reasons. Do it for the fact that this small team (not some large corporation) dedicated large portions of their lives to bring this game to the world, and you are recieving enjoyment from their work, leaving them with nothing. If you buy the game, the devs will get $6 to $7... don't you believe they deserve that?
Think about it.