Straight Lunge involves Little Mac stepping back to charge up a powerful, forward-sliding straight punch. Unlike most chargeable moves, its charge cannot be stored. The charging animation and fully-charged punch grants Little Mac weak damage-based armor from frame 1, which can tank minimal damage; this allows it to function as a counter of sorts and deter juggling in niche situations.
Straight Lunge consists of two phases:
Like majority of Little Mac's moves, Straight Lunge is significantly weaker in the air, and loses both power and travel distance. A fully-charged aerial Straight Lunge will grant horizontal distance, but it is of questionable use as it is unlikely for the move to fully charge in midair, and Mac cannot grab ledges during the entire animation. Straight Lunge is therefore highly impractical for recovery or attacking in midair. Courtesy of its high ending lag and Mac's ineffective recovery moves, using it offstage would also result in an inevitable self-destruct.
Overall, this move is useful as a method for Little Mac to stand his ground, as he will not be knocked back by weak projectiles such as Mega Man's Metal Blade or jab infinites from characters like Fox. In Smash 4, it can also be used as a niche way to punish enemies who are prone to spamming edge attacks. In comparison, the fully-charged version is almost impossible to land during 1v1 matches due to its charge time, leaving it only useful against enemies that have a broken shield.
Like most of Little Mac's special moves, Straight Lunge has a unique 8-bit sound if he is using a Wireframe alternate costume. If Kirby copies him while in that costume, he uses the 8-bit sound along with his own voice.
In Smash 4, Straight Lunge is unique in a few ways: it is the one of the two moves (aside from Ultimate Uppercut) that does not gain damage unless fully charged, as the level of charge only increases the distance Little Mac lunges, while damage remains the same. Additionally, the charging process can only be canceled by letting the move fully charge or by pressing the special button again after around a second has passed.
In Ultimate, Straight Lunge was given additional utility. It can be shield cancelled, improving its defensive and mixup ability as Mac can tank a weak move and have options to dodge afterwards. It can also be turned around when unleashed, allowing it to hit enemies behind him. Finally, the move no longer possesses a blindspot due to the changes to jostling.
Unlike in Smash 4, Straight Lunge's power properly scales with charge time, and the fully charged version consists of a lasting sweetspot. The uncharged version has lowered ending lag, but weaker power (especially in the air), but the charged version is more powerful overall. While the move still possesses armor, the increased damage of edge attacks now prevent Straight Lunge from tanking against them, removing a key ledge trapping option for Mac.
When Little Mac's Power Meter is full, his Straight Lunge is replaced with a single-use uppercut named the KO Uppercut. While it has the word "KO" in its name, it is not a true one-hit KO. Regardless, it is one of the strongest special moves in the game.
Getting a KO Uppercut requires Little Mac to either receive 100% damage or deal 333% damage to opponents (or, more likely, a combination of both) to fill up his Power Meter via his own attacks or melee-based items; thrown items do not contribute to the meter. Unlike other special moves, Little Mac can only safely hold a KO Uppercut for four seconds before it is vulnerable to being removed by any attack that causes Little Mac to tumble.
The attack itself can be considered similar to a fully-charged Wario Waft: it is immensely powerful yet extremely fast, hitting on frame 9 and dealing enough knockback to KO the entire cast at 35% (with the exception of Shulk in the Shield Monado Art). This is dependent on the opponent's weight due to the uppercut's strong vertical angle (Jigglypuff in Smash 4 only needing 12% to be at KO percentage). However, KO Uppercut can be very predictable and risky due to its high ending lag, and the potential to lose it from being tumbled after four seconds. Fortunately, the move's quick startup and Little Mac's excellent grounded combo potential allows a KO Uppercut to combo from many of Mac's moves.
Kirby can use the Straight Lunge via copying Little Mac, but does not gain a Power Meter and thus can only use the standard version of the move.
The attack itself has several properties to note:
Consistent with Little Mac's depiction as a very strong fighter on the ground and very weak in the air, the aerial version of KO Uppercut is drastically weaker, and also becomes blockable. However, using the KO Uppercut while having any sort of forward momentum gives Little Mac some decent horizontal distance, which can help him get back onstage. This tactic can boost Little Mac's abysmal recovery on certain stages, notably ones with walls that allow him to wall jump, although it is a very risky tactic in general, since the move's high ending lag makes it extremely likely that he'll be KO'd anyway.
In Smash 4, KO Uppercut appears as an uppercut that generates sweat-like particles while Little Mac stays grounded. The uppercut creates a small windbox when unleashed; in rare cases, this can force an opponent offstage unexpectedly should they dodge the initial hitbox, and can also cause the attack to miss entirely. The windbox can even be negated by a counterattack's counter frames, making it seem like it was "countered" with no effect to the opponent.
In Ultimate, Little Mac will leap upwards while his front/back faces the camera before instantly returning to the ground, which makes it more closely resemble the Star Punch from the original Punch-Out!!. It is now easier to land overall due to its larger hitbox due to Mac's movement, and can even catch jumping opponents. Its windbox has been removed, which prevents unintentional interactions.
The aerial version now grants good horizontal distance and can be used for an actual recovery due to its ending lag being reduced, but it is no longer unblockable.
Combos into KO Uppercut
KO Uppercut can be easily telegraphed despite its quick startup. However, Little Mac grounded combo prowess grants him a few combos he can use to give himself a better guarantee to land an Uppercut, giving him potentially one of the most potent combos-to-KOs in the game along with more mixups to play mindgames with the opponent.
Special Move customization was added in Super Smash Bros. 4. These are the variations:
*All custom variants of Straight Lunge do not alter KO Uppercut in any way.
The uppercut is a reference to Little Mac's signature moves in the Punch-Out!! series, the Star Uppercut and KO Punch. These moves deal considerable damage, and the KO Punch has a higher chance of leaving Mac's opponents down for the full ten-count.
The power meter originates from the 1984 arcade Punch-Out!! and Super Punch-Out!!. If Little Mac keeps attacking the opponent, the power meter will fill, but taking damage will cause the meter to fall, unlike in Smash Bros. When the power meter is fully charged (indicated by a glowing "KO" similar to the meter in Super Smash Bros.), the player can perform one of two knockout punches, an uppercut or a body-blow, by pressing a button on the arcade cabinet depending on the position of the gloves. Unlike the version in Smash, the player can continue to use knockout punches until they are hit. The only Punch-Out!! game to retain this system outside of the arcades was Super Punch-Out!! on SNES.