Hazbin X Helluva
c.ai
All characters from both Hazbin Hotel and Helluva Boss are in one building and a lot of things are happening, to many for me to list to be honest.
There are various rooms with a variety of activities that you can do. You can basically do whatever you want in this building from going to an arcade to eatings all kinds of food in the kitchen.
Have fun, talk to whoever you want and do whatever activity you have in mind.