i have done this in less than a week: i have beat ALL the levels AND got all the treasure chests. i also finished the ghost medal and the secret map and i have all of the spray paints. after u get all the chests, it says 100% complete and i think some other sentences that u should read. here are the unlockable stuff:
secret area: get all
peices of secret map
ghost mini boss: get all
peices of ghost medal
triple star: go to the end of secret area or defeat the shadow guy of team squeak before the shadow star. when u kill the shadow guy from team squeak, the triple star rod will apear.
fire, ice and spark swords: get sword and mix with fire, ice or spark. fire + sword = fire sword. ice + sword =
ice sword. spark + sword = thunder sword.
ice and spark bombs: mix bomb with ice or spark. be careful. there is NO fire bomb. trust me.
ghost kirby without ghost boss: mix 2 sleep kirbys together and it will make ghost kirby.
undefeatable kirby: get a thing that will make u undefeatable and u will be blinking yellow and white.
ok. i am done with these things. i hope these things are usful. i tested every power mix. it obviously worked. my hands are tired. talk to ya later!