From Outscape Wiki
INCOMPLETE STUB PAGE - WORK UNDERWAY
Skirmish galaxies are smaller. Players start closer together and have a faster start. Ideal for learning the game.
Full galaxies are huge (bigger than Skirmish galaxies) and players have more time and space. Experience long-term strategic gameplay that plays out over many months.
Veteran galaxies are reserved for only the most experienced of players that have already proven their skill in the Main galaxy.