I should hope so. I mean. You DID murder him.
I sort of want to see a little more penitence than “I do repent.” You just killed your (ex?) girlfriend’s father and your family advisor and a high ranking official. You may have only killed a guy by accident (well – not REALLY by accident – you just killed the wrong one) but you have killed a rather important person to your culture. And without any honor, either, when it comes to that. Killing people through curtains is generally not socially acceptable. I sort of want you to feel a little bit bad about it.
I understand why he kills Polonius. He’s worked himself up into such a state…he’s a firecracker ready to explode – anyone could have startled him into murder given his state of mind. But I want him to feel sorry and I’m not sure this line is quite enough to give me what I want.