Apparently the original Doom required 4 MiB of RAM https://old.reddit.com/r/gaming/comments/a4yi5t/original_doo... but I'm pretty sure there have been ports to platforms that had less.

Most of that is static data, so if stored unpacked, a larger flash should be sufficient to make the game need very little RAM. Unfortunately, if I read it correctly, this one only has 1MB of flash. (oh: but SD card. That could work!)

thanks! these are good points!

however, if you have the sd card powered on all the time it will cut your battery life by about a factor of 30

Yeah, most of the 90s home console ports were to systems that had less than 4MB RAM. Jaguar, 3DO, PlayStation, SNES, 32X. The GBA also has less than 512KB RAM and a 16MHz ARM and had Doom and Doom II ports. Some cutbacks might be necessary but probably doable.

Also none of those systems had Flash, and they were all a lot slower, requiring more time/space tradeoffs.

You could build a ray casting engine, textures and maps that would fit in that easily. It might not be doom but something similar is possible.

The RP2040 has 264 KiB of RAM. RP2040 Doom: https://news.ycombinator.com/item?id=30672527

PS. although, the RP2040 has 2 cores and programmable IO controllers, which IIRC were pretty needed to deal with the low memory (and sound). I don't know how this chip compares.

Also, as I just realized, the RP2040 Doom author is also the Pico SDK (lead?) developer at Raspberry Pi Ltd.[1], which probably contributed as much to the success as the two cores and their PIO controllers.

[1] https://www.raspberrypi.com/news/doom-comes-to-raspberry-pi-...

you can get one with 2MB of RAM now: https://ambiq.com/apollo4/