I played it for 3 months. Starting out, and working your way up to battleships and level 4 missions is fun. However, once you get to level 4 missions, the game just lacks skill. Whether or not you win a fight depends entirely on what ship your in, and what gear you have. There is no player skill involved in winning or losing. Also the PvP is rather 1 sided. It is easy to avoid a fight, so if you think your going to lose, you just run away. Likewise, if you can win the fight, your opponent will just run away. So, you can easily go for hours doing nothing but avoiding bigger ships, and having smaller ships avoid you, without any action.
That being said, if you can get a friend to play the game with you, you can start out together, and work your way up to battleships and get about 3-4 months of enjoyment from the game. The early missions actually involve a fair bit of skill, and teaming up to finish them is rather fun.