In case you don't want to bother yourselves with save editors for Risk of Rain Returns.

Go to \Steam\userdata\(random folder name)\1337520\remote and backup your save.json file.

Download this .json file[drive.google.com] and put it in a folder mentioned above or copy-paste the text.

P.S. Here's an Alternative save file[drive.google.com] with no final providence trials completed (no corresponding paints and achievements) in case you want to complete them yourselves.

1. when you enter the game all steam achievements will be completed in a second.

2. All your statistics will be dumped too (if you wanna retain it - copy everything except "stats" and "run_history" parts in your save file using notepad).