Cute game and idea, I especially liked the wonky packages. The controls were a bit too finicky for the small (two tile) platforms and didn't feel that great on ramps. Otherwise everything worked perfeclty fine. A mini map would have helped a lot in navigating the kingdom. Initially I was a bit skeptical about the link to the theme but now I appreciate the meta-implementation of the theme, using the postal service. People seem to underestimate how hard it is to do Pixelart in 48 hours, so I don't think you using tile set use is much of an issue. The only thing that feels off is that your sprites are much sharper than the tile set and could probably use some blurring.