Mike Tyson's Punch-Out!!/World Circuit

Piston Honda
Harder than before. Just fight him normally for the most part (dodge his attacks and go for the stun). He's not as easy to counter-punch.

His special is basically the same as before, but with less startup time. One nice trick you can try - counter his specialty and he'll actually be KOed. Try this at 1:00 of the first round.

Soda Popinski
The least gimmicky boxer in the game. Just fight normally.

There's only one small trick - when he ducks (signifying an uppercut), put up your guard. This will cause him to wait a second: use this time to land a body blow and get a star. If you can use that star immediately afterwards, he'll be knocked down.

Bald Bull
Basically the same as last time. The only big difference is that he can only be knocked down by uppercuts (to remedy this, he now uses a taunt that can be easily "countered" for stars) and Bull Charge counters.

Don Flamenco
Extremely annoying. He has two phases: offensive and defensive. In his offensive phase, fight normally. In his defensive phase, just attack him until he throws his big punch, then dodge and attack. You'll likely run out of hearts here, but it's nearly unavoidable.

Mr. Sandman
He starts with jabs; dodge normally. When he switches to hooks, the fight becomes easier. Throw a punch to his face - he'll dodge, then throw a hook (allowing you to attack him afterward). Repeat this over and over to do big damage. When he blocks instead of dodging, he's going for his specialty - wait for him to flash, then do three quick dodges to escape the uppercuts. (He does his special at the beginning of the second and third round and when either one of you recover from a knockdown during that time.)

During this whole fight, remember that when he's stunned, you can't hit him in the face - you have to go for the body.

Super Macho Man
Mostly pretty basic. When he stands still for a very long time, he's about to do one of his spin punches. The first type comes out quickly and does big damage, and the second one comes out slowly but is done repeatedly and knocks you down in one hit. Just stay on guard.

When he's preparing for a spin punch, try this - tap up, then release and punch him in the stomach to get a star.

"Iron" Mike Tyson
Hardest opponent in the game.

Until 1:30 of the first round, he throws uppercuts that'll take you down in one shot. No matter what, don't get twitchy - only dodge when he punches, or you're almost guaranteed to get nailed. If you want (and you should), you can hit him after each uppercut - attack him with the opposite arm that he threw the uppercut with.

For the last half of the first round, he throws hooks. He telegraphs them by winking - whichever eye he winks with is the side you should punch him on after dodging (but remember that the window of opportunity to hit him is extremely small).

At the beginning of the second round, he throws a flurry of jabs. He won't stop until he throws ten, you run out of hearts, or someone gets knocked down. They're hard to dodge, so you don't want to try and outlast them. Instead, run down your hearts - hit him twice at the beginning of the round (he'll block, but you'll lose hearts), block, do two more punches, and repeat until you're out of hearts with minimal health loss. After that, he goes into his "main" pattern: he'll attack with a hook and then two uppercuts (which no longer are instant knockdowns). From here, just be careful - he usually uses hooks, but if he pauses for a bit, he'll attack with double uppercuts.

At about 1:30 and 2:30 (not always at exactly those times, though) he'll start blinking a lot. Hit him and you'll get a star (or, if you're extremely lucky, you'll hit him at the right time and knock him down). Afterwards, start blocking, because his punches won't stop until you block four. As soon as he stops, get ready to dodge some uppercuts and try to use that star (if you're not out of hearts again).

Once you're in the third round, he gets seriously nasty. He becomes less predictable - he also throws in jabs, which are only signified by long pauses just like the uppercuts, only worse because they have absolutely no startup time - meaning that unless you're already blocking or dodging (a bad idea, obviously) you're going to get nailed.

There's not much to say on that. Just be careful, don't get "twitchy", and follow the bits of advice above.