how can i play with friends via party mode？

[BeliaDeviluke]

Does the game use remote play to play coop? It don't work when she join me and press the jump button ,the ball number(the player number) has not increased....

[Crumble]

Yes it uses the remote play together steam features to play online.
Couple things you could try:
-Try plugging unplugging while in the game
-Try plugging unplugging while out of the game
-Try with the keyboard (you can play one on the controller and one on the keyboard)

Do you have the same problem with other couch coop type of games?

[BeliaDeviluke]

No it's my first time to use remote play ,i will try it when i have my own controller
many thanks to your patient help~
i think your game is good ieda and i hope it can be more popular and more interesting