VGA Planets is a space-combat strategy game. You start with a small empire in a star cluster, together with up to ten other players. Your objective is to enlarge your empire, conquer the other empires, and ultimately rule the galaxy.
You will start by building up an economy, and by exploring the galaxy. Newly-colonized planets give you room to improve your economy - which you will later use to support your demand for warships. And you will use those to make your neighbours' life hard.
You will play one of 11 different peoples, with unique abilities and a unique set of ships.
VGA Planets is a turn-based game. This means all players can do their turn without hurry on their own computer. Unlike in a real-time game, it doesn't matter how fast you play. Usually, there are several days, or even weeks, between turns. Everything that counts is your strategy.
You usually play against humans, which makes every game new and challenging. You don't play the same game over and over, but now in "hard" instead of "medium" skill, you don't play against the same computer again and again which always escorts freighters with a scout.
VGA Planets is a very flexible game, especially with PHost as the host program. It can be tuned to emphasize different aspects of the game - economy, war, equality of starting conditions, diplomacy, etc. Your actual objectives can differ, there can be different missions than just "capture everyone else". This depends on the person who sets up the game.
Planets is easy to learn and hard to master.