Glitch: Saved game deletion:
If the game is played on a classic Game Boy after a game has been saved after play on the Game Boy Color, that saved game file will be automatically deleted.
Hint: Mushroom Town: Defeating first Boss:
When fighting the first Boss, stay far down from where the rock worm goes and it will never hit you. When he comes by, shoot him until he dies. You will not lose any life from him; just a few Conkers.
Refill health
To refill health, if you're almost dead, save the game, turn it off, and when you come back, you'll have four health.