Very nicely made fun little game with even a message and that the end of it.
The goal is simple: you have to this small platformer by jumping only once during each level. That makes you carefully think about your every decision and judge your every move. Plus it fits the theme of the jam perfectly.
The design is very minimalistic but effective and is looks really good.
I don't even think I had any major problems with this game. Like obviously it could've been longer and have more mechanics added in later levels, but that is probably due to the limited time of the jam. The only thing that was a little frustrating was the one life for the whole game mechanic, that was pretty unnecessary, but due to the short lenght of the game it wasn't that big of an issue.
Overall, really good work and if the developer decides to stick with it after the jam, it could be really interesting.