I'm going to preface this by saying that this is an early access game. It does not represent the final product, and should not be considered as if it's a finished game.
Starbound is a really good game. It's fun, and will last you hours on end. You should probably know that this game is basicly Terraria, but with spaceships. Terraria was already a pretty good game, but I should go over a few differences.
The charecter creation allows for multiple species, including humans, Apex, Avians, Florans, Glitch, Hylotl, and Novakids
There are multiple planets and solar systems to travel to
There is more advanced weaponry
You have a mining laser
The biomes include adrid, desert, forest, grasslands, jungle, magma, moon, savannah, snow, tentacles, tundra, volcanic, crystal, flesh, tar, and eventually there will be arctic and ocean biomes.
There is an outpost where you can take missions, buy items, upgrade your ship, and play a maze game on an arcade cabinet
Various things such as Apex labs, or Human prisons, can be found in the world
The world lacks randomized generation, as in it having a set universe with preset planets.