very surprising, even if Quake (the original, my favourite Quake game) had a software renderer that worked quite well. It wasn't uncommon for other games at the time. One of my favourite games to date, the original The Need for Speed III: Hot Pursuit also had a software renderer and while it didn't look as nice as the hardware accelerated renderer, the performance seemed slightly superior to me, at least on my system back then.
The GBA is full of surprises, probably my favourite handheld to date. A SNES in handheld size with added vitamins.
Btw, the EWRAM in the GBA sounds fascinatingly cool when explained in the video.