My first and only criticism - just to get it out of the way - is that the game could have greatly benefited from more generous checkpoints. Remember the target audience of a game jam: people who are going to be playing a lot of games in a short amount of time to see cool design ideas in action, not people looking for a challenge and bragging rights. In this game, sending the player back a full minute for a split-second mistake doesn't help demonstrate the gameplay; in fact, it harms it as it prevents the player from seeing new kinds of obstacles. As it stands, I was only able to get a few checkpoints into the game with the time I had available.
I really like this concept! At first I thought you had forgotten to check if the player was on the ground before letting them jump again... then it seemed basically the same as Flappy Bird. But after a couple of simple obstacles, the game really came into its own! Since all the movement options affected several different variables, it required thoughtful movement; you can't just go right because you also go up. You also can't just slow down or back up, because you'll go up then, too! And you can't just let yourself fall, because you're still moving horizontally and might move into an obstacle. This created a lot of interesting catch-22 scenarios with emergent tactics! I wish I could have seen more of the level design, but what I saw was definitely cool.