This game is not like Terraria
Let's just get this out of the way right now, this game looks like Terraria, and many people mistake it for Terraria, it's even constantly being compared to Terreria, but it is not Terraria, and that's a good thing.
Let's start off by talking about the origins of the game. The dev has stated that the game started with the idea of "A easy to mod Terraria clone." But it changed. In it's current form, just about all it shares with Terraria is it's aesthetic, and that it's a 2d sandbox. Crea, first and foremost, has dramatically different combat. The combat in crea is very dynamic, a lot of dodging and blocking, and with a lot of skills for you to use. There are even combos, and there are several different paths you could go in terms of combat.
Next is the crafting. Crea takes a new approach to crafting compared to other sandboxes, in that you discover he recipes by researching the pieces of the items themselves. The end result of this is that finding a new recipe is more like a scavenger hunt than anything else, as you look for the piece that completes your recipe.
Next is exploration. Exploring in Crea is something that it often feels like there is a good reason to do, in fact, it almost always feels as such. While it doesn't feel like exploration is the core of the game (as, indeed, it isn't), exploration is rewarded, and required. The materials you need are not centered in a small place, they're all over the world, and should you decided to spend most of your time underground, the tunnels always feel more like you're spelunking, than anything else.
The last big piece is modding. This game has possibly the best mod support I've ever seen, so in the future, there will likely be a wide range of different ways you can play the game, all through modding.
So through all of these things, it's really a very different experience than Terraria. While it's not quite TF2 vs COD, it's close in how they're dramatically different, though of the same genre.
Now lastly, it is worth pointing something out. This is early access, there are bugs, there are character wipes, and if you don't want those, wait until the game comes out. However, the primary developer of this game is one of the most active in the community from all developers I've seen. Someone makes a suggestion, he might have it implemented within a day. Someone asks a question, there will usually be a quick answer from him. What this ends up meaning is that the people in early access have a very big impact on the game. When something is implemented which no one likes, the developer changes or reverts it, and listens to the community for suggestions on replacements. What this all ends up meaning is, if you want a stable game wait until it's released. If you want to have an impact on the game, and don't mind dealing with non-game breaking bugs, then get this, it's an excellent game.
One last thing, when looking at the reviews, look at the date, the developer holds the policy that, while in early access, the game should be different enough every two or three months to warrant another playthrough. And almost always the older reviews which had problems with the game have had the problems fixed.
Anyway, long story short, I'd recommend this game.