Can I submit a game that has been made already (less than a month ago) but is being worked on and improved still?
if you want to check the game to see if it is allowed:
itch.io: https://nellowtcs.itch.io/teleporterdash
GitHub src: https://github.com/NellowTCS/TeleporterDash
GitHub website: https://github.com/TeleporterDash/teleporterdash.github.io

Thanks!

Thanks for asking, but no - you can't submit an already made game.

Alright thanks!

You are free to make a demo/variation/remix of it though, following the theme that is announced at the start, and during the jam.