You can also see it like that:
There is no gameplay/story reason to kill the hamster, it’s just “for fun”. Doesn’t this sound even worse?
You put it into a microwave, turn if on, the hamster explodes and leaves a bloody mess (which you can pick up).
There isn’t much more you can show? (At least with this graphics style)
Although this may not be enough to ban the game, what about mass murder? This is a topic the BPjM is particularly sensitive about.