The level of violence in Golion is above average for sure, more like something in an OVA aimed at 20 somethings than a toy commercial aimed at kindergardeners. There is one scene where the king buries a bunch of rebels in the ground up to their heads and then has his soldiers have a contest to see how many HEADS they can COLLECT. There are literally children being cut in half and extremely violent colosseums fights with bloody limbs flying everywhere.
In a show like Zeta Gundam half the cast is killed before the series ends, and there are tons of NPC deaths in every episode, but there is nowhere near the amount of just...ridiculous pointless violence. Its like 10 year olds wrote this show because the killing in Golion is the epitome of gratuitous. There's just no f*cking point to any of it other than it being something to animate. Over the course of the series two main characters die...yet when this happens its barely even shown.
Its a fascinating show, but its not particularly good or anything.
EDIT: I just remembered that the princess's cousin is kept in Syncline's rape dungeon for virtually the entire series. Sometimes she escapes, but until the end of the show she's mainly in the dungeon. Its...pretty obvious she's getting raped down there regularly, and its also pretty obvious that Syncline likes her because she (and the princess) look like how he imagine's his mother (who was human) must have looked.