hidden deliveries/how to activate the tiles: 

Complete the game once and you will discover
the package was yours all the time. 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.