A lot to unpack in those first few panels. The name of the mall is obviously a Back to the Future reference, but while making the comic I noticed two Pi symbols could be read as "Pi Pi" or Pipi, the eggs Spamton uses in battle. That's just an amusing coincidence.
The name of the clothing store is slightly more than a gratuitous Discworld reference. There does exist a clothing store called "Maurices", and Maurice is also a Discworld character (the cat from The Amazing Maurice and His Educated Rodents).
I don't expect anyone to get the reference behind the entertainment store. It's a nod to a local entertainment store I frequented when I was younger called Hastings, which sadly closed down in 2016.
The hotel being called the Masamune is a chain reference. The Excalibur is a hotel in Las Vegas, and in the first Final Fantasy the two strongest swords were the Excalibur and the Masamune.
The penguin blanket is a bit of self-indulgence. I'm a sucker for blankets, pajama pants, socks, plushies, mugs, and just about any cozy cold weather item with penguins on it, and they just happened to fit Spamton perfectly for the reasons Ralsei gives. For anyone wondering, yes, some places do sell blankets in rolls like that. And yes, that blanket brand really is "The Big One," it's a Kohl's line.
So what song did I play the most while working on this? Glad you asked, voice in my head, it was straight from Devil's Crush to Jaki Crush.