Hi there, thanks for playing!
The game was made in GameMaker: Studio, though I really wouldn't recommend it for making 3D games, except you really want to go for that very lo-fi look :p.
The visual assets were made in GameMaker itself and Paint.net, and I didn't even use any 3D modelling software back then, but basically placed individual vertices for the models from code. The Audio was all done by John!