Rain of Stage is a Map and Mod Kit for Risk of Rain 2, providing all the bare essentials for getting started with making RoR2 Maps and Mods.
It is recommended to make a copy of your Risk of Rain 2 folder to work against with Rain of Stages. Doing so will ensure that Rain of Stages does not interfere with the normal operation of your Risk of Rain 2 game and ensure that the version doesn't automatically change when the game is updated so you can update when you're ready.
To use this project you will need a copy of Unity that matches Risk of Rain 2's current unity version. As of this writing, that is Unity 2018.4.16f1.