The main character is shirtless in 3 scenes.

Kissing.

People are shot with a bit of blood. Gun fights and hand to hand combat.

There's a (sort of) offscreen decapitation sort of seen in the background (not really graphic).

Nightwing isn't afraid to hurt the people he questions. We see this when he sort of breaks or twists or does something to a guy's finger and threatens to do so to the rest. It's not too dark or serious, given Nightwing's light and comedic attitude, though that may also be a problem in itself for little ones ready to copy what they see (or, maybe not we're all different)...

One use of b**ls**t