Updating the age-old Game Boy with a speedier CPU and a rather substantially generous colour palette proved to be a shrewd move back in 1998, but even with this hardware upgrade, certain games - such as the iconic Wolfenstein 3D - would always seem out-of-reach. Yet that is exactly what Anders Granlund is pulling off as you can see from the most recent WIP of the game build.
So how did Anders manage this homebrew miracle? He took the Star Fox approach and designed his own special co-processor (aptly codenamed "Wolf") that takes care of all the extra magic needed to perform the deed.
Sadly it looks like the standard 128 kilobytes cartridge ROM will only be able to fit the first episode of the game, with ten levels and three enemy types already taking 123 of those 128 kilobytes in the most current build. That doesn't tarnish the fact that he has accomplished something no one would believe possible on such restricted hardware.