Difference between at the end, finally and at last

[Mahmed]

hi ,

what is the difference between at the end , finally and at last please

thank you

[LearnEnglish2009]

For example:

at last--
the hero killed the king at last.
Did they make it at last?

finally--
finally, we lose the game.
despite the complications, they finally made it.

in the end--
that's him, in the end of the line.
In the end, everyone was happy.