I recognize the knight from the Brackeys' Platformer Bundle!
Echoing what the previous comment said: please don't be disheartened! You've already made it further than you think: you tried and made something. Obviously, there isn't a lot. I don't even know how to get out of the train. But I don't want to disparage. You know what your game lacks, maybe more than anyone else. My point is: nobody asked you to make this game, or join this jam, and yet you did. Keep creating with passion!