in windows there is something called font-smoothing enabled by default. in some cases, this is preferable. for most cases, this is actually terrible. I was playing p99 on my mac using wineskin and noticed that the ui font was muuuuch easier to read, even though the font was set to Arial on both.
the first 2 are font-smoothed (the ones that look like an unintelligible mass of color)
the second 2 are non-font-smoothed (the ones with crisp, defined characters)
https://imgur.com/a/GCA7Vri
to change this setting, simply open the control panel, click system, click advanced system settings (on the left side), click the settings button in the performance section, near the bottom uncheck smooth edges of screen fonts.
you'll need to change fonts from arial to soemthing else and back if you're already in-game.