Hope you enjoyed your first jam! Nice little game, wish it had some sprites and a different mechanic, but good job! 

I liked the song at the start screen but wished the game had some music or sound effects. Since you asked for feedback:

The game would feel a little nicer if holding the space bar didn't constantly make you jump, there were instructions for newly introduced mechanics like holding up to use the ladder, and beating the first level was a little frustrating because your character hits the top of the level on the last jump. Good job on finishing a game in a week!