The first episode has a bit of gore.
Umaru often plays violent games. They don't show too much, just some gunshots with no blood and letters like "Game Over" made by blood.
In a episode there is a tournament of a fighting game. Hits, kicks, powerful attacks, but nothing too much.
Some comical violence, infrequently with blood.
Letters made by blood at the end of a horror movie.
A simulated war in the mind of Umaru. They just show some gunshots, but no one getting shot.