The backstory of my five main characters involves a lot of death...

The protagonist, who has two adopted daughters and raises them alone, lost both his parents and doesn't even remember them (part of a curse), lost his sister, who died giving birth to one of his adopted daughters (I say daughter here and not niece because neither the protagonist nor the sister knew they were siblings), the real father doesn't want to know anything about her, and the other adopted daughter came from an orphanage (it's assumed her parents died as well).

That's the first three main characters and already I have a death toll of five. The other two characters, two brothers, lost a young brother very early on and during the course of the game, both their parents are brutally murdered. So that brings the death toll to eight.

Now, I don't really have a problem using death in my story (as you can plainly see), but at this point, I'm beginning to think I use death too much. My game is actually a horror game with lots of characters dying already (explosive decompression is involved at some point), but even then, should I cut down on the deaths in the backstories of my MAIN characters? Would it feel forced to use death a lot for the main characters?