There have been 7 story arcs so far in the series: The Waluigi Arc (2018), The Rapper Bob Arc (2018), The Anime Arc (2019), The YouTube Arc (2020), The Genesis Arc (2021), the Revelations Arc (2021-2022), and the Lawsuit Arc (2022).
In SMG4: Mario goes to DIDNEY WORL (2017), it is revealed that SMG4 fears his first video he ever made on YouTube. This has been a long running gag as Luke Lerdwichagul (the creator of the channel/series) is very embarrassed about the quality of said video.
Luke Lerdwichagul, the series creator, was 11 years, 11 months, and 13 days old when he released the first episode of SuperMarioGlitchy4.
Before he created the SMG4 series, Luke had originally planned to make his Youtube channel all about glitches (Hence the 'Glitchy" in "SuperMarioGlitchy4"). However, he eventually scrapped the idea at some point due to him not finding the idea very appealing, and also because he found that it was an idea easier said than done for him.
Most characters in SuperMarioGlitchy4 usually don't have people voicing them; instead, what the characters are saying is often essentially translated to the audience by way of subtitles, and over the years, sound clips have been used more and more to accompany the text.