How small can an IWAD be? That's the task I set myself when putting together miniwad.wad.
To clarify the aim, I set myself two additional goals: Doom II compatible, and "vaguely playable". It's not intended to look pretty, but you could in theory play the game this way.
Featuring:
File size is less than 250 KiB, and only 45 KiB when compressed.
BYOL (Bring Your Own Level). The idea here is that you take any of the well-known megaWADs from id