I have created the menu system. I was trying to make one myself, but in the end, I use KidsCanCode's model again.
To be honest? I wanted to make an original one, but it seems I can't as of yet. Guess I should add both licenses of Godot and KidsCanCode.
Anyway, the game is now in the beta state. Need to polish some stuff before finally publishing it.

Sorry for the low-quality gif. First time making GIFs.
Actually, what's the best way to make a GIF? Something I need to learn for future projects.