An absolutely brilliant review, thank you!
I've been offered up many suggestions by others to improve the jumping yet you still managed to provide even more useful ones and I'll be certain to consider all of your critiques in future development.
Also GameMaker is wonderful, it's my first time finishing a game in it. I've mostly worked in Unreal in the past and never realized just how much better life can be in an engine that isn't dreadfully confusing and resource heavy at times so I gotta agree with you there.