This a mod that allows for coop play while using profiles. 2-4 players.
Risk of Rain 2 Splitscreen Mod by BinaryLizard
DISCLAIMER: USE AT OWN RISK still in progress
Step 1: Unzip "BLSplitscreen_RoR2" and enter the file.
Step 2: Now Copy the file labeled "Assembly-CSharp - Modded.dll"
Step 3: Find Risk of Rain 2 local files by right clicking Risk of Rain 2 in steam, then properties, click over to local files,
and press the button labeled "BROWSE LOCAL FILES...". You should now be in a file explorer window with a "Risk of Rain 2_Data" folder.
Step 4: Click "Risk of Rain 2_Data" folder, then into "Managed".
I HIGHLY RECOMMEND NOW COPYING "Assembly-CSharp.dll" and pasting in the same location as "Assembly-CSharp - Copy.dll" at this time
to back up the vanilla file as a fail safe.
Step 5: Once this has been done paste the "Assembly-CSharp - Modded.dll" file and rename it "Assembly-CSharp.dll".
Now this is done the mod is in place and can be used.
Step 1: Open Risk of Rain 2
Step 2: After you select your profile, you will be brought to the menu screen, and now open up the console window by pressing ctrl+alt+`
Step 3: Now type "blsplitscreen" and how ever many players you would like 2-4. For example "blsplitscreen 3" would use existing profile that was selected
and display 3 cursors for 3 player splitscreen.
YOU HAVE TO USE A CONTROLLER. Just press esc to close the console.
Side note. This new update is fairly robust so it will no longer crash the game is something is typed wrong. It will just display an error and continue on.
Also if a number less then 2 and greater than 4 it will select the number of players closest to the number provided.
If you have any questions feel free to ask me, u/binarylizard on reddit