Very nice for a first game!
It was a very nice choice of music, it really suited the games art style and theme.
For any future games You are planning I would recommend working more on animations. When your character is standing still he should have just a very small animation (Like some kind of bobbing). It makes the game feel more dynamic in my eyes. Also when he jumps it would feel more satisfying if he had a more fluent animation.
Also you might want to have him jump not as high. The lifts became unimportant when he could jump that high.