Hello banana boy noobs, HTML is a markup language which is only to create the elements of a webpage. You can make a game with HTML & JavaScript but it would be a web-based game which you would have to host somewhere so that people can go to the link to play. I would suggest that you make sure if HTML or Web games are allowed in this jam, I am pretty sure they are but just make sure.
you totally can and under the partner section on the jam homepage there is a link to https://ctjs.rocks/ a neat Javascript game engine with a a GUI builder as well. Under the docs section of ctjs there are 3 style of games with detailed tutorials to follow to help you get started https://docs.ctjs.rocks/tutorials/
