History YMMV / GameTheory

** Some of his videos covering then recently released games are sponsored by game developers of said games (i.e. the ''Franchise/{{Halo}}'' armor video is sponsored by Microsoft). Some fans have accused [=MatPat=] of having a conflict of interest and turning into a corporate SellOut. However, some fans don't mind that [=MatPat=] is making a quick buck from video game companies given his background as a StarvingArtist 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''.

** In his theory covering the ''ARG/EditorWilbur'' ARG back in 2021, Mat had the thumbnail of the video have the caption as "Face of a Killer?", and posited in the video that Wilbur was an unstable killer responsible for attempting to kill the editor Kai for threatening to reveal he murdered a woman. In 2024, many were quick to find the video aged like milk, as creator and focal figure of the ARG Music/WilburSoot would face accusations of being abusive to his ex-girlfriend Shelby Grace/"Shubble", with many more coming forward with their own accusations, one even accusing him of sexual assaulting, Wilbur even ''admitting'' to some of the accusations even if trying to downplay the severity of them. This resulted in Wilbur being blacklisted from the ''WebVideo/{{QSMP}}'', many of his ComedicSociopathy moments being taken in a much harsher light, and [=GT=] fans noting that Mat's theory was ''very'' accurate to Wilbur now, just replace "Killer" with "Abuser".

** In his theory covering the ''ARG/EditorWilbur'' ARG back in 2021, Mat had the thumbnail of the video have the caption as "Face of a Killer?", and posited in the video that Wilbur was an unstable killer responsible for attempting to kill the editor Kai for getting in his way of being Jack's editor by revealing he murdered a woman. In 2024, many were quick to find the video aged like milk, as creator and focal figure of the ARG Music/WilburSoot would face accusations of being abusive to his ex-girlfriend Shelby Grace/"Shubble", with many more coming forward with their own accusations, one even accusing him of sexual assaulting, Wilbur even ''admitting'' to some of the accusations even if trying to downplay the severity of them. This resulted in Wilbur being blacklisted from the ''WebVideo/{{QSMP}}'', many of his ComedicSociopathy moments being taken in a much harsher light, and [=GT=] fans noting that Mat's theory was ''very'' accurate to Wilbur now, just replace "Killer" with "Abuser".

** In his theory covering the ''ARG/EditorWilbur'' ARG back in 2021, Mat had the thumbnail of the video have the caption as "Face of a Killer?", and posited in the video that Wilbur was an unstable killer responsible for attempting to kill the editor Kai for getting in his way of being Jack's editor by revealing he murdered a woman. In 2024, many were quick to find the video aged like milk, as creator and focal figure of the ARG Music/WilburSoot would face accusations of being abusive to his ex-girlfriend Shelby Grace/"Shubble", with many more coming forward with their own accusations, one even accusing him of sexual assaulting. This resulted in Wilbur being blacklisted from the ''WebVideo/{{QSMP}}'', many of his ComedicSociopathy moments being taken in a much harsher light, and [=GT=] fans noting that Mat's theory was ''very'' accurate to Wilbur now, just replace "Killer" with "Abuser".

* BaseBreakingCharacter: While [=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 ''WebVideo/{{Petscop}}'' video, and Nugget in the ''VideoGame/DuckSeason'' video), has led to them becoming this.

* WinBackTheCrowd: [=MatPat=]'s recent videos, especially his Minecraft lore theories, have been much more warmly received for being well backed by evidence and intriguing.

** Mat was one of the many people who thought ''VideoGame/HelloNeighbor'' would be the next ''FNAF'', and spent several videos before its release trying to determine the theme and plot in advance, the entire time demonstrating how excited he was for the game to be released. Upon its actual release however, he suffered HypeBacklash and was so irritated by the [[ScrappyMechanic gameplay mechanics]], that his next and, as of now, ''last'' theory on the game was about proving how the physics of the ''boxes'' don't work, just to get ''some'' catharsis out of how much he disliked the released product, outright saying how much he ''hates'' the game now.

* CriticalBacklash: During the first half of his tenure as the host, ''Game Theory'' built up a significant amount of criticism, with [=MatPat=] taking the brunt of it as the face of the channel. However, the second half of his tenure would see many YouTubers getting into massive scandals left and right for legitimately serious reasons, and so potshots aimed directly at [=MatPat=] would increasingly be met with defense of, even from people who disliked his actual videos. Even [=MatPat's=] past controversies have been [[https://youtu.be/SmcPL1oqLWg reexamined]] in his favor though others still garner potshots, particularly the 'Sans is Ness' theory. Still, this is probably why the announcement of his retirement in 2024 was met with respect across the Internet, even from his critics.

** There was a significant one with the ''VideoGame/{{Undertale}}'' and ''VideoGame/{{Deltarune}}'' fanbase for nearly a decade. Initially, this was due to many of his early ''Undertale'' theories receiving large amounts of vitriol from the ''Undertale'' fanbase, as well as the Pope Francis incident. However, it reached new heights in 2019 when Creator/TobyFox [[https://twitter.com/tobyfox/status/1081239086847967232 publicly admonished]] [=MatPat=] for falsely advertising ''VideoGame/{{Heartbound}}'' in a Let's Play as being connected to ''Undertale'' and not properly linking to it in his video descriptions. Despite Toby only lightly criticizing [=MatPat=], with the latter apologizing, this incident was blown up by the community as being bigger than it was, and was cited as evidence of bad blood between Toby and [=MatPat=]. Not helping was the fact that not a single ''Undertale'' or ''Deltarune'' theory was made after this, even after the widely-anticipated release of Chapter 2 of ''Deltarune'' in 2021 (even though this was more likely due to the aforementioned vitriol that UT/DR theory videos got). This was only truly quelled in 2024, when in response to the news of [=MatPat=]'s retirement, Toby [[https://twitter.com/tobyfox/status/1745048357846859798 publicly thanked him]] for his videos and even posted art of [[MemeAcknowledgement Sans and Papyrus in Ness outfits]], confirming that no bad blood existed between them.

* CriticalBacklash: During the first half of his tenure as the host, ''Game Theory'' built up a significant amount of criticism, with [=MatPat=] taking the brunt of it as the face of the channel. However, the second half of his tenure would see many YouTubers getting into massive scandals left and right for legitimately serious reasons, and so potshots aimed directly at [=MatPat=] would increasingly be met with defense of, even from people who disliked his actual videos. Even [=MatPat's=] past controversies have been [https://youtu.be/SmcPL1oqLWg reexamined] in his favor though others still garner potshots, particularly the 'Sans is Ness' theory. Still, this is probably why the announcement of his retirement in 2024 was met with respect across the Internet, even from his critics.