I built a neural network using DOOM games A developer publishing as mottopanikeiku released doomformer v0.1.0, a project that compiles integer neural networks into DOOM levels so the game's voodoo dolls, conveyor belts, lava lines and doors perform the arithmetic. In the MNIST demo, 1,355 voodoo dolls run the network and all 248 computed values — hidden layer, 45 score comparisons, 10 win counts and the one-hot answer — matched a NumPy integer reference at tolerance 0, with all 30 walked digit variants (0-9 in three variants each) read correctly and exactly. A READ pass took 5,705 game tics, or 163 seconds of real-time DOOM at 35 tics/s (79 seconds wall time), and the package installs via pip on Python 3.11+ for Linux or macOS. Neural networks that run on DOOM's game mechanics: voodoo dolls, conveyor belts, lava and doors. Watch the films https://mottopanikeiku.github.io/doomformer/ A number is a crowd of voodoo dolls on a conveyor belt. An activation function is a staircase they have to climb. A matrix multiply is dolls running across lava lines, each line raising a room's light level. Attention is dolls squeezing under ceilings that another number has lowered. When the dolls stop, the light levels are read back out of the running game and compared bit for bit with an independent integer reference. One value off by one and the run fails.