Bug: Use Kirby and eat Yoshi so you copy his eating ability. Then eat Yoshi to turn him into an egg. The person playing as Yoshi must quickly mash buttons and the control stick to break out. When Yoshi is free, he will be smaller. This can be done over and over again, making Yoshi smaller and smaller. He can even get as small as a single pixel.
Bug: Mr. Game & Watch has his Oil Panic move where he can catch 3 projectiles and throw oil back as an attack. But if he catches 3 of Ness' PK Flash attacks, a glitch occurs where if Game & Watch moves at all, he will explode violently and be sent flying off the screen for an instant KO.