I would most likely classify it under "adventure science fiction", although there will be action, it's not one of the main "selling-points" of the game- which is more about the adventure and moral (or immoral, if that's how you chose to play) decisions.
The max health is 120, (there will be opportunities to gain even more health, like special protective equipment and such), but the starting health is 100. I want it to be somewhat realistic- but again since action isn't the main point it depends on what you do.
For example, if you get shot, you'd lose a large amount of health points, 20 if it's somewhere vital for fighting like the leg or arm, 40-50 if it's somewhere deadly like the chest or stomach, you lose all 100 if its the head, which is where things like the equipment can come in handy, but only 5-10 if it's in the hand or foot or somewhere less useful. But if you get punched because you annoyed someone just a bit too much? Okay, maybe you lose 2 health points, maybe it's only 1 if they're a weak hitter.