Description[]
Decorations are purely cosmetic, they provide no income, neither coin nor mineral or items. Decorations can also be used as a wall, not being able to be destroyed and covering more ground it is a useful way to use them. A difference to the wall also is the price. The cheapest decoration is the radar for 2000 coins, the streetlight 1 chip. Whilst walls come back after being destroyed, decorations cannot actually be destroyed.
Moreover, some decorations can be used to hide turrets (however spies can always see these turrets).

Sentry Tower[]
“ | The starlings believe they are the true eyes of planets! | ” |
— In-game description |

Radar[]
“ | It's constantly sending out signals to look for more Starling leaders. | ” |
— In-game description |

Streetlight[]
“ | Starlings are kinda scared of darkness... so having these can help. | ” |
— In-game description |

Sphinx[]
“ | These rare ancient statues are all that is left from previous civilizations. | ” |
— In-game description |

Hammock[]
“ | Nothing like a Starling book and a Hammock after a long day of work. | ” |
— In-game description |

Graves[]
“ | Honoring our brave fallen heroes. | ” |
— In-game description |

Plant[]
“ | Be careful with the young ones, this attractive plant is carnivorous! | ” |
— In-game description |

Tree[]
“ | These mineral fiber trees light up the Starling planets. | ” |
— In-game description |

Billboard[]
“ | Cause all Starlings dream of seeing their picture there. | ” |
— In-game description |

Fountain[]
“ | Throw some minerals and make a wish! | ” |
— In-game description |