SMG4: If Mario Was In... Starfox (Starlink Battle For Atlas) is the forty-sixth episode of Season 8 and the four hundred and forty-second overall to be uploaded by SMG4.
The episode begins with Mario walking down the street when he found Bob begging for cash. Mario was immediately suspicious at the sight of this, as he remembered that Bob owned a carnival that earned him a ton of money, especially during the events of SMG4: The Mario Carnival. Bob nervously claimed that he'd donated all his money to charity, which was an obvious lie. So obvious, in fact, that not even Mario fell for it. When that didn't work, Bob feigned illness and claimed he was sick with "Butt's Disease." Mario still didn't fall for it. Suddenly, a spaceship appeared in the sky, with a panicked Slippy Toad frantically trying to work the controls. It landed right on top of Bob, causing him to shout out his famous catchphrase, "Ow! My ovaries!" in a high-pitched voice.
When the smoke cleared, Mario pried the ship open and found Slippy inside, badly injured. Struggling to breathe, Slippy told Mario that he'd been attacked by aliens, which made Mario think of Nicolas Cage's E.T.. Slippy tried to ask Mario to call an ambulance, but then his ship suddenly started to shake. It ejected Slippy and sent Mario flying. Suddenly, Mario landed inside the cockpit and the spacecraft took him to space. Once he left, Bob faced Slippy and got him to start begging for money, which he agreed at gunpoint.
Meanwhile, Mario was up in space with Slippy's ship, happily messing around with the controls. He figured out how to work the ship's communication and weapon systems, using the latter to blow up random objects with missiles, until he accidentally rammed into a much larger spaceship and was knocked unconscious.
Mario later woke up inside the latter ship, tied up and bound to a chair. Standing in front of him was Mason, who proceeded to slap Mario in the face. He angrily asked who Mario was and who he worked for. Scared and confused, Mario told Mason his name and that he worked for spaghetti. Mason remarked that he'd "never heard of that race before," then introduced himself and Fox McCloud to Mario. Mason explained that he and Fox were pilots who worked for Starlink, a task force which functioned as a defender of the galaxy. Fox was getting impatient, though, and he ran into the room yelling at Mason for taking too long. He then slapped Mario multiple times and asked him where Slippy was. Mario couldn't give a coherent response because he was dizzy from all the slapping. Suddenly an alarm went off, and the ship's monitor showed that several enemy ships were attacking. Mason and Fox dropped everything and fought back. They wiped the enemy out easily, but then an even bigger group of ships appeared. Mason panicked and thrust the ship forward at top speed to escape the enemy ships, which caused Mario to break free from the chair. He then approached the control panel and offered to help. Mason told him not to touch anything, but Mario didn't listen, claiming he had "a 200 IQ." Mario pressed a button, which caused the ship to self-destruct.
Later, Mario woke up on a strange, desolate planet, with the wrecked remains of Mason and Fox's ship nearby. Mario began to look around to see if anyone else had survived the crash when he suddenly heard a small voice say "Pingas!" Mario looked down and saw that the voice had come from a tiny head of Dr. Eggman he accidentally stepped on. Mario picked it up and tried to figure out what it was, but then Fox appeared out of nowhere and tackled Mario. He yelled at Mario for crashing the ship and furiously asked him what he was thinking, to which Mario simply replied that he "saved the world". This angered Fox even more, and he told Mario that he and Mason didn't need Mario's help, but then Fox realized that Mason was missing, so the two went looking for him. After a while, Fox, who was desperate to get off the planet, asked Mario if he happened to have a ship. Mario said he didn't, but he did find the Robotnik head in the sand.
Fox asked what it was; Mario naturally said he didn't know, but he did know that it made funny noises when squeezed. Mario then demonstrated this by repeatedly squeezing the Robotnik head to make it say "Pingas!" over and over. Fox groaned, muttering that he was wasting his time. After a short while, he got annoyed by the Robotnik head and demanded Mario to stop squeezing it. Mario, of course, did not obey, and Fox tackled him again, this time with the intent to kill him. Just then, though, Mason showed up with his ship fully repaired. Overjoyed to see Mason and the ship again, Fox suggested they leave Mario behind and go home. Mason said they couldn't though; he explained that they had crash-landed on the planet Sonatus, and it was in grave danger.
The trio took a ride in the ship. Someone stepped on Fox's tail, and he asked who was doing it, which was Mario. Mario said it was Mason while Mason told them both to keep quiet and behave, but Mario again didn't obey and started singing the Witch Doctor song, which angered Fox into trying to kill him again. Luckily, they reached their destination before another disaster could strike; they'd arrived at a drilling station guarded by the same enemy ships the trio had encountered earlier. The drilling machine was digging tons of Robotnik heads from the ground. Mason explained that the aliens were on a mission to get more powerful by mining the universe's most valuable resource, memes, out of every planet they could find. Memes were the power source of everything in existence; if a planet was completely deprived of its memes, it'd cease to exist. This shocking information caused Mario to become hysterical, which sent Fox into a rage trying to calm him down. Mason yelled at them both to calm down before telling them not to worry as he had some secret weapons. He then reconfigured his ship to reveal a slew of guns that were built into the ship and that he could swap between them at will. He plunged the ship straight into battle and took the enemy ships head-on, shooting them down with a whole bunch of weapons including a laser gun, a freeze ray, and even a black hole cannon. After the enemy ships were cleared out, the trio flew in to take out the drill, but then they got shot down. The three heroes were unharmed, but they heard an evil laugh as they emerged from the wrecked ship. It was then that they saw who the leader of the operation was: Fox's arch nemesis, Wolf O'Donnell.
Wolf taunted them, explaining that he was going to use memes to power up his alien army, then exclaimed how happy he was to be able to kill them all, especially Fox. Wolf then sent his alien ships after the friends, and Mario started squeezing his Robotnik head out of fear. The head said "Pingas!" and the enemy ships suddenly stopped short. Mason was surprised at what happened and then told Mario to squeeze the Robotnik head again, so he did. This time the ships lowered themselves and landed on the ground. Mason told Mario to keep squeezing the head. Mario finally got where Mason was getting at, so he set off a dance rave and squeezed the head again and again. This drove the aliens piloting the ships to come out and have a dance party with Mario. They were now completely under Mario's control, so he had them destroy Wolf's drill so he couldn't steal Sonatus' memes. Wolf swore his revenge and flew away, and the friends celebrated. Then Mario asked what they were going to do next, and Fox and Mason drove him back to the Mushroom City and dropped him off, right back where he was before their little adventure in order to prevent Mario’s antics from annoying them. Mario then ran into Bob and Slippy, who asked him for money.