Ass Pull: The theories on Mario and FNAF have been accused of having rather contrived explanations that focus too much on speculation instead of hard evidence or confirmation by the creators. In particular, the "Mario is Communist" video has been criticized for focusing too much on red coloration as added to represent communism when most programmers view the red coloration more for color contrast. (Though in that case, he acknowledged the ridiculousness of the theory at the end.)
When people complained that there wasn't any sponsor in the Is The MMO Genre Dying?, MatPat later put an annotation saying this video was sponsored by Game of War. However, this soon lead to even more backlash from suspicions that the sponsor affected the outcome of the theory.
His W.D. Gastervideo addressed criticism leveled at the Sans Is Ness video and Game Theory as a whole by reiterating that he doesn't try to claim his theories are canon and is only trying to introduce alternate ways of thinking based on evidence that may support what he says. Much like the above, the actual results of this were... divisive.
In more recent years, it appears that even Mat realized how ridiculous the Sans is Ness theory was, and has made it a Running Gag.
A common complaint about MatPats later theories is that they were stretched out to be far longer than his earlier ones, and that extra time was being used to make unfunny jokes instead of fleshing out the theory. Since these complaints, his videos have been consistently shorter.
Matt was in the process of making a video on the Empire's "Fire Storm" weapon part of the Operation: Cinder plot shown in Star Wars Battlefront II (2017) that Electronic Arts originally offered to sponsor. When the Loot Crate and In-Game Economy controversies broke out and created their own fire storm, Matt decided it was better to distance himself from EA and declined the sponsorship, but elected to upload the video as it was most of the way done. He also added in a foreword at the start of the video explaining the situation and mentioning his stance on the matter.
As mentioned under, Older Than They Think below, Matt has received criticism in the past for not acknowledging when a theory he's stating is actually an already established fan theory, instead of one he himself made. In his theory on Doki Doki Literature Club!, however, he specifically acknowledges and gives credit to the specific Redditors who found evidence that he himself was incapable of deciphering.
The first episode Petscop received a large amount of criticism from the series community for entirely basing it as a telling of the Candace Newmaker case, a interpretation that was largely debunked as just thematic references. A year later, MatPat did a sequel video where he avoided the same mistake.
Kirby - Dream Land's Biggest Threat was the first part of a planned two-part theory that used evidence from the games to indicate that Kirby was actually a destructive force of chaos rather than the protagonist he is usually portrayed as, with the second episode being planned to tie this in with Void Termina and other lore from the series. However, the episode received a lot of criticism for seemingly cherry-picking Kirby's motives as well as discounting the fact that he is still only a baby, which accounts for most of his decisions; there was also the fact that the lore that the planned second episode would focus on had already been elaborated on by many other Youtubers. In response, MatPat instead made a different episode focused on Kirby's flight ability, creating a disclaimer at the episode beginning explaining his choices and acknowledging the criticism leveled towards his original theory.
Awesome Music: "Science Blaster", the opening theme for the series that was made specifically for the show.
Base-Breaking Character: MatPat's decision to personify both Nugget and Monika in their respective games' theories was met with positive reception by fans, the reappearance of those characters in later theories that have nothing to do with them (Monika appearing in the Petscop video, and Nugget in the Duck Season video), has led to them becoming this.
The channel has a fairly large number of Five Nights at Freddy's videos (without counting livestreams), even more than Mario and Zelda theories. Either you love how much attention he gives to the series and the fans or you're sick of it and hate MatPat for pandering to FNAF fans so much.
Lampshaded in his YouTube Rewind/Facebook's 2015 Year in Review. Still doesn't solve the problem about having tons of FNAF videos, but at least he's aware that maybe he gave too much focus on Freddy and Pals.
As noted below in the Internet Backdraft entry, MatPat's smug and quippy attitude in some of his videos has been a sore spot of contention. Some fans don't mind it or even find it hilarious, while others find his persona to be excessively narcissistic and egotistical, especially when he claims to know better than the game than the creators working on them.
Some of his videos covering recent new games are sponsored by game developers of said games (i.e. the Halo armor video is sponsored by Microsoft). Some fans have accused MatPat of having a conflict of interest and turning into a corporate Sell-Out. However, some fans don't mind that MatPat is making a quick buck from video game companies given his background as a Starving Artist struggling with depression and unemployment. Not helping matters is the fact that the "Is the MMO Genre Dying?" video has been accused of ignoring other successful forms of MMO monetization like Buy-to-Play, making it seem like an obvious pro-mobile gaming video and advertisement for sponsor Game of War.
Two other shows hosted on the channel, Game Drake's Crossover and Gaijin Goombah's Game Exchange, have garnered their fair share of contention. Crossover's attempts to link unrelated franchises is either amusing or as contrived as Game Theory's more infamous theories. Meanwhile Game Exchange is widely praised, studying the cultural influences, especially Japanese ones, in games, but it has also been criticized at times for defending games (notably Metroid: Other M) that aren't well liked outside of Japan, though this backlash may be due to Values Dissonance.
In 2016, MatPat announced he would host a new show, Game Lab, exclusive to the subscription-based YouTube Red. While many fans were excited since it focuses more on hard science instead of random fan theories, several were worried that MatPat's commitment to Game Lab would divert attention away from his Game Theorists and Film Theorists channels, possibly negatively impacting their quality.
MatPat's gamer-centric episode in which he gave Pope Francis a copy of Undertale. The fan reaction was polarizing to say the least; in general, most people applaud him for trying to show a more positive side to gaming culture and for advocating the use of games to espouse empathy among people. Some are skeptical about MatPat's claims and feel that his references to recent tragedies was untimely and inappropriate regardless of his intent. Others just thought that the video sounded really pretentious. It should be noted though that his idea of using games to help improve society and promote empathy isn't without precedent, shared by many other intellectuals like game designers Jane Mcgonigal and James Portnow.
His third Undertale theory, not so much for the theory itself, but rather for the part of the video where he discusses the negative reception of the first two Undertale videos. Some people feel bad for him, agreeing that the backlash was unwarranted and went too far, while others argue that he deserved the criticisms for releasing unsatisfactory videos, and his attempt at justifying them screams of Never My Fault.
His second Petscop theory, not because of the theory itself, but because of the video, which exhibits intentional audio glitches, eerie edits, and an overall uneasy tone. Some praised the video to be among Game Theory's best edited, creating an atmosphere that meshes with the topic's horror and mystery elements perfectly, while others felt that it was actually too effective, scaring them to the point that they couldn't even finish the video.
In general, the argument that each video's point is that "it's just a theory", and that they are ultimately supposed to be taken with a grain of salt. On one hand, some agree that the theories are only really for entertainment, aren't really being asserted as truth, and that the detractors are taking things too seriously; on the other hand, detractors believe this is essentially using the fan theory equivalent of It's Not Supposed to Win Oscars to excuse poor research and questionable sourcing (or lack thereof).
MatPat: So in the end, what have we learned today? Don't jump off of buildings. You will die.
Critical Research Failure: One of the points MatPat brings up in his "The Metroid Morph Ball is LAME" is that crawling would be just as effective as using the Morph Ball. This completely disregards any of the power-ups from that series that would be difficult or impossible to use otherwise such as any of the Bombs, Bomb Jumping, the Boost Ball, the Hyper Ball, the Spider Ball, etc.
He gives Handsome Jack this treatment in his Borderlands 2 video, arguing at the end he really is the hero wanting to bring peace while not mentioning some of his more grievous crimes from the games, like his murder and torture of innocents, running the city of Opportunity like a dictatorship, and ejecting four innocent scientists out an airlock on the mere suspicion that one might be a traitor, giving Moxxi and Lilith decent motivation for betraying him. However, the theory can be defended on the grounds that the theory only applies for the first game, and doesn't outright excuse him of his actions, merely presenting him as a Fallen Hero.
Ensemble Dark Horse: The portrayal of Nugget by MatPat's wife Stephanie during their playthrough of the game proved to be quite a hit with fans, leading to Nugget appearing in a number of other videos and even the official channel banner.
Face of the Band: MatPat; as far as most people care, Gaijin Goombahnote Game Exchange and Culture Shock, Ronnienote DNSQ, Drakenote Smash History and Crossover, and Kennynote Also does Crossover don't exist.
Fandom Rivalry: With Gnoggin, a similar show on YouTube, to the point where flame wars have broken out in the comments of videos on both sides. It doesn't help that Gnoggin has made at least three videos specifically to discredit MatPat's theories, and several people treat Gnoggin as the "Let's talk smack about Game Theory" channel. There's also the allegations that the Game Theory about Smash Bros. being about Masahiro Sakurai's disillusionment with the series and the games industry in general is directly ripping off Gnoggin's theory about Super Smash Brothers being about living with autism. Another point of contention is MatPat doing an amiibo theory one week after Gnoggin, with the exact same theory.
All the jokes mocking MatPat's infamous "Sans is Ness" and (to a lesser extent) "Why I Gave the Pope Undertale" videos become this when MatPat addresses in "Who Is Gaster?" that the hate and ridicule he got from those videos had really cut him deep.
MatPat's jokes about his treatment of his editor Ronnie, often comparing it to slave labor, becomes much harder to watch after Ronnie died by suicide.
Harsher in Hindsight: Mat's speech about a friend he knew back in choir who he stopped from completing a suicide attempt becomes far sadder when Ronnie died by suicide later that year, with MatPat releasing a video in late July talking about Ronnie.
He Panned It, Now He Sucks!: His constant jabs at Nintendo, the Wii U, and some of their franchises (Mario in particular) is known to really rile up Nintendo fans, especially ones who outright detest the Game Theory fandom for acting like MatPat's theories are 100% fact (when they're not supposed to be).
MatPat states that Princess Peach is the evil mastermind behind the Toads. He sort of got it it right that Jen Taylor voiced a Big Bad who controls a horde of monsters, but got it wrong as to what which medium she's from.
When talking about the announcement of Ultimate Custom Night in the "FNAF STUMPED ME" video, MatPat remarks that it "Might be time for Markiplier to give up his FNAF crown". Once the game came out, Markiplier actually did eventually give up on beating 50/20 mode.
Hype Backlash: As Game Theory is considered one of the most popular non-"Let's Play" channels (with 9 million+ subscribers), it's natural that some will hate MatPat for his overexposure. Among all his videos, his Mario and FNAF ones are among the highest viewed yet also the most polarizing, with some viewers criticizing these videos for having too many research errors and relying too much hackneyed guesses instead hard science and history.
Going with the above, some feel that MatPat has begun to display a lot of narcissism in his videos by making it sounds like he knows better than the creators of the very games he does theories on. Even before his Five Nights at Freddy's 4 video, he displayed a similar attitude by completely disregarding the official canon timeline made by Nintendo for the The Legend of Zelda franchise.
The internet was not happy about the poor research that was put into the "OVERWATCH vs TF2" episode of Deadlock.
During one of his live streams on GT Live, Matpat mistook Heartbound for a successor of Undertale, mislabeling the game, refusing to call it by name, and not even linking to it in any way shape or form, resulting in the developers, Pirate Software, calling out MatPat for this misinformation. This wasn't the end of the problem however; MatPat dug in his heels, refused to make any sort of apology, or correction, and stated that the exposure alone was good enough. The backlash was bad enough to the point that Toby Fox himself called him out on how unhelpful and damaging that sort of thing is to developers trying to make a name for themselves. He has since apologized for this error, and later said in his tweet to begin revising the way his team tags/titles livestreams, along with linking the games to their download sites. This however still has the unfortunate effect of making MatPat look disingenuous, since it took the creator of Undertale calling him out for him to actually do anything about it.
YouTuber Legal Eagle has made a video saying that Matpat plagiarized his video on the legality of Fortnite dances. This combined with the incident about has escalated the situation.
It's Not Supposed to Win Oscars: MatPat ends each episode by claiming that it's "just a theory", and fans have interpreted this as meaning that his theories should be exempt from critique, and any "debunking" responses are taking it too seriously. Of course, this ignores the fact that, in the scientific world, MatPat's "theories" (which are actually closer to hypotheses than theories) would naturally undergo lots of peer review, so saying it's "just a theory" to ward off criticism would be completely missing the point.
"LINK IS DEAD!" (from the infamous Majora's Mask video usually detested by Zelda fans who stick only to canon information and hate it when Game Theory fans parrot said theory like it's a fact).
"SANS IS NESS!" is even more popular online but in this case it's mocking his badly-researched Undertale and EarthBound video.
"Sens," in mocking reference to the Sans is Ness video. It has become a small Running Gag among fans of "high quality video game ripper" SiIvaGunner, particularly with "rips" involving music having to do with Sans or EarthBound.
After MatPat infamously gave the Pope a copy of Undertale, the internet was awash in people parodying the event.
Narm: It's kind of hard to take you seriously when you grimly talk about Mario being an unfeeling sociopath while you're constantly cutting to Mario grinding Luigi's shoe in as both brothers awkwardly grin like it's the worst thing ever.
Nausea Fuel: Some episodes, some as Why Star Fox has NO LEGS and BEWARE Link's Hookshot! contain very detailed studies of real-life human anatomy.
Many research failures are usually forgotten by the majority of the viewers but a few of them are so absurd no one can forget it. "Wario is practically 10 feet tall" and "Sans is Ness!" are easily his most quoted mistake and are always mentioned when someone is trying to make fun of the channel.
The channel being overrun with FNAF videos is not a reputation it will escape anytime soon.
Older Than They Think: MatPat did not create a number of the theories, he simply put them in video form. Ones such as "Cloud accidentally killed Aerith" or "Rosalina is related to Peach" (though not the part about Luigi being Rosalina's father) have been floating around for years. This brings even more fuel to the fire that is the Game Theory and Gnoggin Fandom Rivalry, since Lockstin in the past made videos on theories that didn't originate from him and has given credit to where it's due (Jar Jar Binks Sith theory) or flat out admit a theory idea isn't his own (Bowser is dead and possessed theory).
Mario has constantly been on the receiving end of this from MatPat himself ever since his theory where he is portrayed as a sociopath. Nintendo itself sometimes gets this treatment oddly enough, especially during the Wii U arc. This has worsened in his "Toad's Deadly Secret" episode, where he proposes that Peach is the true Big Bad of the Mario franchise, using her parasitic followers to run the Goombas out of their native homeland, with Bowser as the tragic, reluctant Big Good just trying to combat a parasitic threat.
Parodied in the Harry Potter video when he mentions that Ron is Voldemort.
If their playthrough of Doki Doki Literature Club! is anything to go by, Mat and Stephanie consider the protagonist a sociopath.
Phoenix Wright got this recent treatment as well, being accused of tampering with the crime scene and presenting unknown evidence, failing to acknowledge that prosecutors Miles Edgeworth (pre-HeelFace Turn) and Manfred von Karma have done far worse. In the same game, no less.
His Cuphead theory asserts that Cuphead and Mugman are selling illegal alcohol and, thus, are no better than the literal devil. While it can be argued that committing something illegal is wrong, no matter the scenario, considering many people, both then and today, saw the Prohibition as a big joke (which, as MatPat himself even acknowledges, is the main reason why it was so short-lived), trying to make them morally equivalent to Satan isn't really fooling anybody.
Seasonal Rot: The sentiment among older fans is that Mat's newer theories (especially the ones that have to do with lore instead of math and science) have increasingly become more flimsy and farfetched, prone to being easily debunked due to cherry-picked facts and/or rushed research, and seemingly made for the sake of getting attention or a personal gripe, rather than coming to an actually plausible conclusion with the episode's theory. Usually cited as the worst:
The "Mario is Mental" videos, for using anything as proof that Mario is a cruel sociopath.
Are MMOs Dying for being an obvious ad for a mobile game, taking the idea of a sponsored video to a whole new level and ignoring actual successful and current MMOs.
The Undertale Sequel to EarthBound Theory. To keep it brief, Mat ignores the lore of both Undertale and EarthBound, makes stretches far beyond logical, and he cites an old Rom Hack that Toby made during his teenage years that he considers a total Old Shame.
Snark Bait: MatPat has pretty much caused Game Theory to become this with a lot of people due to his outlandish theories, the infamous "Sans is Ness" theory, his attacks on Nintendo and Mario, and the most infamous and controversial of all, his Stalker Without a Crush theories on FNAF, especially when he puts himself as knowing more than Scott Cawthon.
Squick: MatPat believes that both the "mental" theory and the "timeline" theory hold up; in other words, even though Jumpman is clearly stated in the latter theory to be Mario's father, Mario is still a dangerous sociopath and man whore. What he fails to realize is this: if Jumpman is Mario's father, and Mario is potentially seeing Pauline on the side, then...yeah.
Awesome Music: "Phase Shift", the opening theme also made specifically for the show.
Even Better Sequel: His first DHMIS Theory received quite the praise. The second part was widely regarded as a satisfying and well-reinforced theory, possibly even MatPat's best. It helps that he outright said his theory wasn't the only possibility and cites the creators as a reason to watch other theories on the show.
A straight example of the latter is his theory that the main cast of Rogue One isn't heard of or mentioned in the Original Trilogy as they've turned to the Dark Side, and he takes the time to dismiss the idea of all of them being dead by the end of the movie, because would Disney/Lucasfilms really kill off their new characters in their Star Wars spin-off? Yes. Yes, they would.
The thumbnail of the video dealing with Article 13 features a graphic of Spongebob Squarepants being ground up. Only three days after the video was uploaded, series creator Stephen Hillenburg died of ALS.
MatPat argued that the tuppence in Mary Poppins would have been worthless had Michael put it into the bank. Come its sequel, and it turns out the tuppence ends up being what was needed to save Michael's house.
MatPat constantly jokes that his Film Theories predicting future events don't actually happen, citing Rogue One, Last Jedi, and other such movies. Come 2019, though, and two of his theories, Black Widow dying in Avengers: Endgame and Dany becoming the Mad Queen in Game of Thrones, end up becoming correct.
It's Not Supposed to Win Oscars: In his Zootopia video, MatPat cautioned viewers that his Film Theory and Game Theory series are intended for introducing people to new ideas that they can then research themselves and that the videos shouldn't be taken completely at face value. Given how his Zootopia video does discuss controversial real life topics like the War on Drugs and police brutality, it's probably for the best.
Same as in his Game Theory videos, MatPat has the tendency to not always distinguish between his own theories and those he is simply regurgitating, the most egregious example being his Game of Thrones theory. Not only had the R+L=J theory existed for years (and is easily one of the most well-known fan theories around), but certain terminology in the video (such as encouraging fans to come back to the video once the theory is inevitably confirmed in show to congratulate him for being right) has irked certain people, since it sounds as if he's actively trying to claim credit for it.
His Simpsons theory on Where the Hell Is Springfield? is more or less commonly known Simpsons trivia and not some mind blowing theory like he made it out to be.
Ron the Death Eater: Jumps onto the bandwagon that the trolls from Frozen are evil and had manipulated Hans into turning evil.
Rooting for the Empire: His habit has even spilled overinto his Film Theory videos, where he goes on about the economic impact of the destruction of the Death Star, while twice dismissing any possible effect of Alderaan's.
Uncanny Valley: Many of the episode's title cards tend to have characters with shocked faces on them. This isn't particularly bad if the character was already shocked, but they're often photoshopped with this face and the results are...unsettling.
Win Back the Crowd: His Don't Hug Me I'm Scared theory has been more warmly received, for using far less shaky evidence and logic than his more infamous theories. It helps that this was a long-requested theory as well.