This is a really fascinating concept, changing your movement options dependent on whether your in night or day. However, the way you have it set up right now is incredibly frustrating. I'm not sure how you would go about improving the concept, but maybe changing it from a on/off situation to a gradual one could work out. So the closer it gets to night, the weaker your left/right movement is, and the stronger your jump power, vice versa.
Like the slime's design tho! Very cute.