Hey, thanks for the feedback!
Unfortunately, all of these issues have to do with the lack of time (Lots of job-related hassle to take care of in tandem with the jam) we had to polish the game, haha. We had a few more features planned to spice up core jumping mechanics, but didn't get a chance to code them. All of these points are valid and, chances are, we'll come back to this thing later with a big patch. Stay tuned!
Will definitely have a look at your game!