This mod aims to redo all the arenas in the main campaign by making them more interesting and a lot harder. Kind of like Encore levels except it all takes place in the original levels instead of brand new ones (Use Configgy to switch between Nemesis and vanilla)
Generally I tried to use interesting enemy combinations and to play into the environment/level geometry so that you approach things in more unique ways and such. The new encounters aren't limited in enemy types and late game enemies can appear from the very start. So I recommend beating Fraud if you haven't done that yet
Nemesis levels also save your progress separately and they have their own rank requirements
Currently the mod is in development, so only some layers are changed. I'll update it as I finish each layer:
Done (1/10)
Upcoming (9/10)
Also because of the nature of the mod, boss levels would need some special treatment so if you have ideas then dm me on discord @somebilly
if you can p rank everything in Billion Nemesis on Billion Difficulty i'll be impressed