Indie game storeFree gamesFun gamesHorror games
Game developmentAssetsComics

There's a weapon maker mod that gives you code for a customized gun.

For mutations you'll usually have to learn some coding and/or ask around unless it's something very basic

Ok thanks for the help!

 I'm on currently making some guns for a mod pack that I can hopefully upload 

One of them is making an infinite minigun with custom sprites, ill let you know how it goes