We're fairly open minded about how the logo may look, although it does need to look good at smaller sizes. It does need an icon that may be used, rather than just text, and the word "Starfare" may be included as part of this icon or alongside.
Please not cartoony.
Some details on the game:
The core aspect of the game is expanding your empire by colonising planets.
There are three factions in the game that are dependant on each other (traders, police & pirates). Each faction belongs to its own star system and operate differently.
Planets may be rapidly colonised using crystals that are acquired with difficulty. You can see such a crystal in the in-progress concept art included.
There are spaceships, star systems, battles and all that good stuff.
Do what you think will stand out and suits the theme!