Hint
When surfing the net I discovered that loads of people don't know where the hidden deliveries are and how to activate the tiles. It's simple. Complete the game once and you will discover the package was yours all the time. I don't know if it is random, but when I opened it the first time I got some roller-skates. Now you will be sent back to the levels where there are tiles that will give you this ability. If you find a tile then there is bound to be a portal near by which can only be reached with the skates. Go in and you find that there is a bonus stage in which you have to spell the name of a certain character (Bugs Bunny, Duffy Duck). Get all these in order and go into the portal to be issued with a medal. Complete the game again and you will get a new piece of equipment.