Sorry for being ignorant, but....
in what way is this game any different from Terraria? So far from what I've gathered it's a) access to multiple worlds in the same game through space travel, b) spaceship customization and c) different/more organized crafting/quest menu.
Is there more? seems VERY "terraria 1.5" to me just from watching videos... :x
- Increased difficulty; Terraria was easy as shit after you got a little armor and a decent weapon, but Starbound has multiple galactic sectors with increased difficulty.
- More environmental variety: Terraria really only had 5 biomes; forest, desert, corruption, hell and jungle. Maybe we can count the dungeon as a 6th. They later added ice and crimson, but the crimson was just a red replacement for the corruption so it doesn't really count. Starbound, on the otherhand, has Forest, Jungle, Ice, Moon, arid, desert, ocean and who knows how many others we haven't seen. Plus, Mini-biomes that occur within them (for example, an oasis in the desert). And if we count Terraria's dungeon as a biome, then we have to consider all the mini-dungeons all over Starbound too.
- Stronger survival aspect: In Terraria, all you have to really worry about is not getting killed by zombies on the first night and you're usually able to progress without any survival aspects. Starbound requires you to watch your food and temperature to survive. Might also be different atmospheres and gravity levels later.
- More weapons / armor / races / building materials. Yeah, it's just 'more', but it still counts for something.
- Not programmed by one guy who likes to take month long breaks and hits his limit pretty quick (the networking in Terraria is dismal, for instance). The support over this first week has been pretty damn quick.
- Very modable. People are already doing very cool things in this thread. Terraria had mods, but the developer never really embraced that part of the community and provided no support for it.
And beyond that, lots of 'little things' that just fit nicely into the sandbox; musical instruments, ship customization, monster capturing, fossils (after launch), etc.
Also, I fail to see how being "A better Terraria" is anything wrong, especially when Terraria was in developmental limbo for a year and ended up still being pretty 'meh' worthy after their 'biggest patch ever'.