That’s cool! Always cool to read when someone finds an entry point to broadening their gaming horizons!
I’d highly recommend
Enter the Gungeon
Nuclear Throne
FTL
The top two are fun frantic top-down shooters where you can feel yourself getting better between runs, barring terrible RNG luck of course. (But fighting against the odds is cool too.)
FTL is just a very “tight” experience. I’m sure other games have perhaps improved on its principles but it’s focused and knows exactly what it wants to be.