The sequel to the infuriating but clever and cute Hapland has been released. It's called Hapland 2 (or Hapland2) and the walkthrough for this is quite complex, so I've linked to one someone else has done.
If you just want hints, here's a couple:
Acid rain + cannonball = flaming cannonball
If you turn it on, the staircase will move
Homicidal work mates are distracted by butterflys
Via, as always with these things, the incomparable Jay Is Games