Eclipsis may require teammate to play with especially when you are playing against other team with more than one person. About 3~5 people are enough for a single match, and these are the 3 major positions that each person has to be.
Person who controls other positions, usually making strategy. Can also focus on attacking, with other positions like soldier or mechanic. Can also work as a supporter.
Person who builds structures to gather iridiums. Can support builder or mechanic.
Position that builds defences. Has to cooperate with mechanic to build turrets.
Position that is in charge on attacking other teams, may need help from mechanic.
Position that builds barge, needs a lot of support from soldier , engineer or captain.
Supports other positions, requires a lot of experience about the game and pipeworks.