There are currently several known planned game modes for StarForge.
Creative is a game mode that as of Build 0.4.6 spawn the player(s) in a valley with many mountains and several trees around their Respawn Vat. Resource Pallets will continually spawn up to a max of five of each kind of resource.
The game ends when the Leeches destroy the Vat and the player or players are given a stats screen that tells various information about their defense including damage taken, time lasted, enemies killed, and a rank from Peasant to War Hero.
Fort Wars is an unreleased Player vs. Player game mode as of Build 0.4.6 that will be introduced later on. The goal of the game mode is for two opposing teams to destroy their counterparts' Respawn Vat before their own is destroyed.
The game ends when one Vat is destroyed and triggering the win or lose scenario.
Survival is an unreleased Player vs. Environment game mode where the player must survive by gathering resources to create weapons and structures.