The best replacement for starbound is terraria.

The best alternatives to starbound are rated as following:
★★★★★  terraria
★★★★★  edge of space
★★★★  rust
★★★★  minecraft
★★★  terraria 2
★★  signs of life
★★  space engineers
★★  darkout
★★  dayz
★  starmade
  don't starve
  terraria 1.2

Your alternative for starbound is not listed? Suggest!
Speaking about starbound, one probably shouldn't forget about hamachi.

Other search terms related to starbound and their ratings are:
★★★★★ hamachi
You have in mind a companion for starbound and it is not yet here? Propose!



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starbound
terraria
edge of space