Throughout the whole play he keeps saying he wants to avenge his father’s death but he takes not concrete actions.
He is all talk but no action; he doesn’t kill Claudius until the end of the play when everybody else is dying. Hamlet does not live up to his duties as a prince, the state is facing an imminent danger yet he spends relatively little time thinking about the threats to Denmark’s national security. As the prince of Denmark he should be preparing for Fortinbras, imminent attack rather than contemplating
suicide.
Fortinbras character is a foil to Hamlet character, both Fortinbras and hamlet have deceased fathers and uncles that are ruling the throne. The difference between the two is that while Hamlet sits around contemplating life and death, Fortinbras takes immediate action by raising an army to reclaim Norway's lost territories. Fortinbras character is a representation of what a prince should be as he does not wait for orders but instead give orders. The difference between these characters highlights Hamlets inability to a make decision and act.
I think that hamlet was not really interested in killing his uncle but rather felt the burden to carry his father’s revenge plans. He says “The time is out of joint. O cursed spite that I ever was born to set it right”. This demonstrates that he is not really interested in avenging his father but it his filial duty to do so. I think that the reason why he is so indecisive in nature is because he wasn’t too thrilled about the plan to begin with.