how do i make the last one explode?

I 'think' i know what you mean now......

In the gameover function you are just checking if the aliens=0 but you also need to check if it still exploding.

Something like this should work:

Function gameover()
	
stillexploding=False

For explosion.explosion=Each explosion
	stillexploding=True
Next

	If aliens=0 And (Not stillexploding) Then 
		
		;nextlevel=True
		
		flushmemory()
		End

	End If
	
End Function