It was initially made for the5k 2002. Unfortunately the contest got cancelled so I waited for an opportunity to release it while adding more features and optimizing the game beyond all my expectations.
A total of 144 textures are generated based on 6 base textures, 3 tone maps and 8 mathematical patterns.
To render not only the walls but also the floor and ceiling in a size efficient manner, floorcasting was favored over the traditional 2 passes rayscating approach. Using mirroring and time coherence between frames allowed for a frame rate of 10-15fps in Internet Explorer, back in 2002.
Use the arrow keys to move and turn around, x and c to strafe left and right, and space to shoot.