Hey Itchid, sorry about the late reply and thank you for asking! We've discussed this with the team and I also agree with the above quoted rule of Ludum Dare.
You're right that using Godot is bang on for the jam. We won't disallow you from posting your game here, we prefer a game that was made for the theme and for the jam as that is its main purpose, at the same time we want to keep it friendly and mellow a jam where people are encouraged to create, discuss, go wild and feel good.
Bottom line, there's still a lot of time left, if you're up to the challenge why not make a new game for the jam? ;)