Hidden Deliverers:
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. 
Repeat the above. Not hard.