Somehow this is reminiscent of a classic NES game "Ice Climber" especially with the jumping sfx. I like it! 😊 Was it inspired by this somehow? I could also see a hint of Celeste. 😄
Anyway, the game felt complete, found no bugs at all, got very challenging when level was flipped in different ways. In the end, I only managed to get to the blue level because of a few reasons...
So to further improve your game, here are some thoughts.
Ever heard of coyote time? It's a feature where you create an extra window to perform an off-the-ledge jump, or whenever you initially fall. This imperfection will allow for a smoother flow in traversal. The player will be able to jump even without stepping on any platform, but it'll feel much better to control. There are more other platforming features out there, so take a look at them all. 😁
Another thing is I feel like the player character's controller isn't centered. Whenever I press left or right, the whole character seems to move ahead, and gives me a sense that I lost control of the character. Probably it's just the effect of a delayed camera movement. So for a fix, have the camera follow a point a few distances ahead where the character is facing. This also enables the player to see and plan ahead.
I hope this will help you and other than that, CONGRATS! You did well on your 1st game jam ever! Keep it up!👏