I reversed engineered the MegaDrive for 35 years ago and build my own hardware development kit, got a blog about this project at https://nestenius.se/hardware/how-i-built-my-own-sega-mega-d...

[1] https://gbdk.org/

[2] https://www.gbstudio.dev/

The game experience was completely immersive, and it strangely felt both futuristic and absolutely belonging to its time at once. It was pure Zen of gaming. Oh yes, and the grass was greener, of course..)

Flashback is still the #1 game ever for me, followed by Earthworm Jim and Mortal Kombat.