Ending for Wario Land 4 on GBA. This is on Hard Difficulty.
It's difficult for me to explain how to get the best ending but I'll try my best. There are a total of 4 main bosses in the game, if you beat them very quickly, you'll earn 3 treasure chests from each of them. Now the longer it takes for you to kill the bosses, the less treasure chests you'll earn so using your tokens to use special items is absolutely necessary for the best ending.
Once you get the chests from the bosses, you then have to beat the END BOSS before those 12 chests you earned, disappear (ugh like I said I have a hard time explaining this crap, thats why I don't write walkthroughs)