Hey there, here are my thoughts on your game:
The double jump feels really nice and makes for some gameplay. although it took me a while to figure out that I could double jump. there may be an attack of some kind but the B button just bugs the game out big time. I couldnt get past much of the intros to the levels until I figured out there is a double jump.
I would recommend a short intro level that teaches the player the basics. This way, you can be sure the player knows how to play before you throw them against enemies and death pits that require a double jump.
The graphics and readability were quite good, probably the strongest aspect of the design (although there is a bat that is black against a black background in the Egyptian level. That needs a white outline around it at the very least.
I would appreciate the option to select a new level if I want and also be more generous with checkpoints. Ultimately, I stopped playing because a death took you all the way back to the start of the level.
Also, the hitboxes are too large for the enemies and it seems the player hitbox runs as high as the top of the antenna. I would make them smaller so that the gameplay is less frustrating.
Its is an ambitious project for a 7 day jam and the bugs are very real here but it also shows much promise post jam. Well done and keep it up.