Congratulation on your first game AND your first game jam! I have not seen the tutorial you are talking about but it sure must have taught you a lot.
The character feels fun to control, and all the art is good.
What you have to do now is make sure the player has any idea what to do before you throw a challenge at them. Remember that players don't know what you were thinking while you were making the game!
If you have more time, please try to be more intentional with your level design. Instead of placing blocks how it "feels right", choose a particular skill that your're testing the player on, and make a small section of the level about that, then repeat.
I hope you have fun creating more games! :D
PS: I can understand the struggle with text, I remember my first time with Unity I couldn't get it to render smoothly.