Route summary
The main difference between Any% and Best Ending / 100% are the Rainbow Drops. Each world has one Rainbow Drop and collecting all 7 and defeating King DeDeDe at the end will unlock the game's real final boss, Dark Matter. 100% involves doing the Best Ending route while also completing all 6 Bonus Games found in Worlds 1 through 6, as well as collecting one Gooey Girl throughout the run.