As your Captain gains experience, you' unlock new features in the game. For example, at level 6 you unlock the ability to revisit previous timelines, which lets you replay old missions to find alternative solutions (and hidden rewards).
As you continue to gain experience, you’ll unlock new ways to play the game - from PvP Arena Combat to forming Fleets with your friends and allies!
In addition, each time you Level up, you'll gain a little boost in the form of a full and immediate Chroniton recharge.