Basics:
Turn based, 4X, empire space builder, singleplayer, asymmetric, Emperor focused grand strategy.

Core features/promises:

You will feel like the Emperor (assassins, imperial court, granting audiences, rebels, imperial officials)
No micromanagement (no moving individual ships around or constructing boring farms, you deal with more important things)
Unique mechanics (if you are bored with other games and wanted to see something fresh, you won't be disappointed)

The premise behind the game.
You are the emperor, not a logistics officer. You don't deal with low level stuff like building farms, factories or individual ships. Instead you focus on the grander scale of things. You grant audiences, make edicts, appoint imperial officials, deal with court factions and assassins, crush rebels, decide on production quotas and priorities.

In the game there is no micromanagement, late game does not drag on forever. You can play a relatively fast paced game on a huge galaxy without late game slow downs. You own hundreds of planets, thousands of ships and all this is managed on the high level by edicts and a hierarchical fleet system. The whole premise was to make the player make only the important and interesting choices leaving everything else abstracted.

Another important feature is the asymmetric nature of the game. The AI plays by different rules, and does not try to win the game. Aliens are more like creatures living in the galaxy than computer controlled players. Sometimes they can be valuable assets worthy of protection and sometimes an obstacle to overcome. Aliens are not created equal, some are primitive beasts that shall be cleansed from the face of the galaxy, some are fellow humanoids inferior to Terrans of course but considered sentient and worthy of compassion.

In short it's a fast paced turn based space empire builder with no micromanagement, asymmetric mechanics, and focus on you as the emperor.

Stellar Monarch achievements