A very interesting 2D take on the sandbox genre
Basically it's a sandbox/2D platformer mix with RPG elements. You start out with a bunch of basic tools, and it's up to you to collect resources and craft items out of them, including building a home which can range from a basic wood hut to colossal screen-spanning castles.
If like myself you haven't played any sort of game like this before it's a real treat. The graphics are nicely done to convey that nostalgic 8-bit feeling, complete with suitable music. There are very few stats - no levels, for example, your character instead progresses by crafting better equipment - so this game is fairly easy to get into for the casual player.
There are several events which can happen in the game, from the arrival of NPCs when you prepare suitable habitation for them, to a few "boss" fights - which are mostly optional. The game is still being worked upon by the devs so the current seeming lack of overarching goal will probably not be the case for long. Still, there's plenty of things to do and lots of places to explore, and the game does have enough in it that you'd easily get sucked into it. I didn't realise a whole 3 hours had passed during my first foray in, for example.
Some people may prefer to spend their time building grandiose structures. Others may seek the thrill of combat, digging into the unknown to find enemies. There's also a multiplayer component and if you can find a stable server (they're player-hosted, which means they're often only up when the host wants to play...) it can get quite exciting especially if you manage to join a friendly PvP one.
One other thing: loay1152 wrote a pathetic excuse of a "review" a couple of entries previous to this one. Typical of the fanboi mentality, he accused the game of being a ripoff of another one, and gave it a score of "1". As we all know, you can dislike something yet credit it with a proper score, like for example I hate FPS games but that does not mean I am justified in giving Halo, TF2, etc all "1" scores. Because the games are actually good, it's just that they're not my style.
It's pretty obvious that loay1152 is just a tool - and a rather dimwitted one at that. The rest of the drivel he posted is in similar vein, throwing a tantrum like your typical spoiled 8-year old, "wahhh this sucks, wahhh that sucks", displaying the usual limited vocabulary of your average youtube comment poster.
He can't even get the "facts" (as opposed to the other points which were just opinions) right, "all you do is build" and says you have adventures in the game this supposedly copies. Wow, huge fail there: combat is a large component of this game, totally unlike the others. Yes, it's optional and largely avoidable especially if you stick close to the surface areas, but it's far from as tranquil as other sandbox games are.
From all the drivel that loay1152 posted it becomes obvious that he took one look at this game and like the typical internet idiot flew off the handle because it "dared" to "ripoff" some other game he liked. This is especially clear when pretty much all the other reviews give the game decent-good reviews in the 7+ range.
Don't listen to the crazy people, Terraria is a pretty solid implementation of the sandbox genre. For a mere $10, it's worth it, especially considering the devs are actively involved on their official forum and have already released (for free!) a couple of updates, with more on the way.
This is your chance to wean yourself off of Hollywood-style Big Industry gaming, stop sucking EA's and Sony's teats. There are plenty of good indie games and Terraria is a good example.