Great Game
You can buy different ships, different weapons, different armaments, receive loot for missions, that can be sold for different prices at different places you go.
This is a deep game with a lot of options to keep it fresh. The missions are not too long and while they are basic story elements like escort missions, it is the challenge of the enemy that will make the missions fun.
The only aspect lacking is the sound, and I think that is more a problem with playing on a phone than a fault of the game.