I'll add some rules if people want to do this I guess-
You can only use the pistol for the whole game (I recommend using the pigeon) and if you run low on ammo you can still kill enemies so no ammo won't be a problem
1- Stick with the pistol (ALWAYS)
2- Choose pigeon (since they start with pistols)
3- You CANNOT choose another gun beside a pistol
4- feel free to reset a run if it doesn't go well (no penalties)