I'm working on a ground-up rewrite of this mod. It should be out soon, and available here, and on Thunderstore. It will have all the same featuers and more, but with much better performance, and actually maintainable.
ULTRAKILLtweaker is a mod for Ultrakill that lets you tweak various things.
You should probably watch this tutorial by nptnk. If you don't want to though, here are instructions in text.
- Follow the Bepinex tutorial here, up until 1:10
- Unzip the UMM.zip file into ULTRAKILL\BepInEx. Make sure you are using release 0.4 or later. Do not use 'Recompile for ACT-2 release', it may appear at the top but it is not the newest.
- Go to ULTRAKILL\BepInEx\UMM Mods and delete CustomArms.dll (unless you want the custom arms).
- Download a release and unzip it into the ULTRAKILL folder.
- Open the game, click the mods button, click on ULTRAKILLtweaker so it is green and tick the box so it is crossed.