Don't beat yourself up, it doesn't suck and like Mehcro said, you at least made one and dared to submit it for the whole of itch.io to see and evaluate.
I do agree with some of the feedback here, it is very unpolished still and feels unfinished. So perhaps you made some bad choices here and there, but the platforming itself works quite well. It plays fluently, gravity feels ok, so playability is quite ok.
I would say it's a very good start! Don't let negative feedback put you down, but take it as lessons and improve the next time!