Hiya! We're using the new version of GameMaker! ^^
Ah, thought so!
I assume your all set for the time being, but if you ever need some temporary help from someone familiar with the platform, I would be willing to assist with the project.
Keep up the amazing work, the gameplay and engine are amazingly fine tuned! (the art and music are amazing too of course) I played the demo a year ago and I still go back to it for reference when trying to get certain movements to feel better lol