In general, this series has a surprisingly small amount of actual combat, but in general:
Giant robots battle in dramatic environments
Robots from space crash into Earth in a dramatic Raid
Robots expel red fluid similar to blood when damaged
Mild hand to hand combat takes place frequently
A man battles giant robots with nothing but a sword, cutting off limbs and impaling them
A man is fitted with an electric shock collar that is comedically triggered to paralyze him at various times
Some more detailed scenes include:
Ep. 7: A mother slaps her daughter in an argument, it's an emotional scene.
Ep 8: A father punches his son in front of a teacher in a shocking display of verbal and physical abuse, though there are no repercussions for the act, and it's tacitly treated as accepted behavior.
Ep 10: A man is kicked by a robot, and begins to bleed where he lands.
A man breaks his own hand to escape being a captive
A man's neck is broken by another man's bare hands
Ep. 11: A man is impaled by a sword, blood drips down the blade.
A man is shot repeatedly by a machine gun
Bodies are seen in pools of blood
Two Samurai battle with swords, one is impaled before falling and making a bloody impact
Ep13: A man is impaled by a sword, a small amount of blood is shown.
Season 2:
The action picks up in season 2, but is overall less graphic than the first season. A handful of people are stabbed and slashed with knives and swords.
Ep. 14-15. A man coughs up blood and bleeds from wounds, getting blood on his hands and on others.
Ep 26. A character is impaled on a sword and a prolonged discussion takes place with him while the sword is sticking out of him, some blood is seen.