A steep learning curve makes it difficult to get into, but with time you find an impressive game.
Gameplay:
The Gameplay is simple you move jump and use a variety of tools and weapons with the mouse. As a 2D game the movement is simple and works quite well. Now comes my only problem with Terraria, it doesn't want people to enjoy it. Terraria is the type of game which simply drops the player in a randomly generated world with no mission no tutorial no help at all. A guide is helpful in the sense that random pieces of information can tell you a couple things you didn't know, but they offer little support. It is almost essential to look at a guide for the first part of the game as you may not understand what you should be doing, and that works fine, but I wonder how the initial players must have felt. Even with your bearings the game still takes time. As you develop a rhythm and understanding there is a ton of fun, but this can take hours and may turn many people off.
Presentation:
The game is a 2D game with a simple art style. Terraria is not pretty by any means but the art style works in an interesting way. It could look better but as an indie game it is understandable.
Verdict:
A plot-less game with a steep learning curve may turn many people off. But, for the value of $10 or four for $30 it may be worth it to experiment. Many people may find the time required to fully enjoy the game overwhelming, but a deep and satisfying experience awaits those who are patient.