The design style is more accurately labeled "neo-brutalism", which is characterized by these bold colors.
gumroad is one of the most popular examples: https://gumroad.com/
gumroad is one of the most popular examples: https://gumroad.com/
Neobrutalism adds color and bold design to brutalism, but maintains the simple focus on structure and function. NB features prominent and simple shapes to delimit UI elements and buttons, and bold and prominent typography.
NB is not "Retro" nor "cyberpunk", and it doesn't add in superfluous details and decorative elements. You wouldn't use Emoji in NB when a simple bit of plaintext would do.
Good for the OP for working hard to create something very fun and unique, but it is not Brutalism nor NeoBrutalism.
Otherwise, I was more concerned with the approach to software development and bloat