Like the minimalistic artstyle and the effect. There are a few things I should change if you wanted to change your game a bit after the jam. Doesn't mean you need to do this, just some feedback.
The control feel a little bit floaty sometimes:
You can change this for example by adding some more gravity and also enlarge your jump force so you keep the same jump height.
The jump feels not that powerfull sometimes:
When you dubble jump but already have a downwards velocity your resulting jump velocity will be low or 0. You can change this easily by first setting the downwards velocity to zero. Also I should add a bit more in air movement
Sometimes the camera clips or moves back to the player:
When you are moving and stop moving the camera will go back a bit to the player, this is probably intentional. But sometimes it feels that you are going slow and takes away your ritme.
Audio:
The sound effect sound a little shrill but it's okay if you lower your volume. I don't know if you wanted some music in your game but it's very easy to just generate a song. I did the same for my game on "Strofe".
Further more I really liked the idea of repeating the level and always making it harder.
That I gave you a lot of feedback is certainly not because you made a bad game, you should be proud of what you made and this on 7 days. Good job!