Note that this feedback is based on the build(s) available at the end of the jam.
XO appears to be a striaghtforward and functional tic-tac-toe/naughts and crosses game, and with that in mind, there's not a lot of meaningful feedback I can give.
There may be room to add audio, fancy graphics, and AI, but I think that you accomplished what you set out to make, and so long as you learned something along the way, that's a great outcome in my eyes!
Thanks for submitting and best of luck with the project if you continue development! :D