up to 4 players, with seperate health bars, either online or local.

[dude98]

since undertale together has 2 player with seperate health bars, and they have a 4 player one as well, could we possibly get 4 players versus sans all at once using the keyboard or maybe chrome's gamepad support?

[dl-tg]

This is just replication of sans' battle. Not some fan game. I am 100% sure such thing will never be added, firstly because it completely misses point of the project, secondly the creator probably abandoned the project, thirdly you can add it yourself, the project is open-source. Fork the repository and do anything you want, don't forget to credit the author.