Players have to manage their inventory and their character's skills from their base. From there, you can not only save the game, but also choose the missions that you want to accept. And you can accept a lot of different ones.
Once you've accepted a mission, you have to complete it any way you want or can. For example, a mission might be to steal data from a computer, and in order to do so you can either use stealth... or kill all of the security guards and civilians that you meet along the way.
Graphically speaking, DataJack is quite similar to the legendary game Syndicate, and it even has the same setting and perspective. However, despite the retro esthetic (or maybe because of it) the game stays good the whole time.
DataJack is an excellent stealth and action game with hints of role-playing, which will remind you of Syndicate in a way that won't displease veteran players.