Help skinninng for retro games Thread

Hi new to the forum. Looking to get a basic understanding on how they skinned games lets say for the playstation. Some of the later era playstation games looked great for the hardware. What I'm trying to do is learn how to design a game on hardware constraints or more specifically for hardware like a playstation (50mhz/750mb etc)

I'll be using gimp, blender game engine, linux and a dual core laptop I bought on ebay for 50 dollars. Any help would be appreciated. Thank you