Tom Forsyth made the original port of Doom to the GP32 but it was in a very early state and was slow, had no sound and various bugs.
Craig and myself (Guyfawkes) decided one night to continue the work on the game and some time later transformed it into a great port of the classic game. It now had a fancy boot menu to choose various options such as custom wads, set the CPU speed, sound and various other features.
Rob then offered to work on rewriting much of the file access routines which was causing us some problems especially when loading WADs and saving and loading. So Craig and myself took a back seat and a short while later Rob had completed his work resulting in an even greater port which was now pretty much complete.
Several months later Craig and myself decided to work on the game a little more as the game was incompatible with the newer GP32 BLU+ consoles. As well as fixing the incompatiblity problems I fixed some outstanding bugs and while doing so I noticed that we found a unneded CPU speed setting which results in a massive performance increase!
The port is pretty much perfect now and in my opinion the best port of Doom found on any handheld device!