New top story on Hacker News: Ask HN: How were video games from the 90s so efficient?

Ask HN: How were video games from the 90s so efficient?
53 by eezurr | 46 comments on Hacker News.
Title says it all. I am interested in discovering how games like roller coaster tycoon, sim city 2000, warcraft II, and descent (blown away by this one) managed to be created and function on computers that had 500 MB HDD, 300 MHz CPU, and 4 MB RAM. I'd even broaden the question and ask how did windows 95 stay so small? Is it possible to recreate this level of efficiency on modern systems? Im curious because I'm interested in creating simulation video games. Dwarf Fortress and Rimworld eventually both suffer from the same problem: CPU death. If I create a window with C++ and SFML, 60 MB of RAM is used (not impressive at all). If I put 3,000,000 tiles on the screen (using Vertex Arrays), 1 GB of RAM is used (admittedly, that is impressive) and I can pan all the tiles around smoothly. What other tricks are available?