Honestly, I felt pretty frustrated playing. Partly because I don't play a lot of platformers, partly because of the control scheme, and party because of the lack of the difficulty of the first level and lack of guidance.
For me jump is always space on the keyboard and shift is dash so I couldn't overcome the muscle memory of dashing with spacebar when I wanted to jump. There also isn't any guidance on what to expect. Am I supposed to be able to reach the orbs by dashing and jumping? Am I supposed to sequentially wall jump to reach the orbs? Additionally, once I got to the next character the "rules" of the game were still unclear: Does my current character affect the physics of the previous character?
The platforming itself was already difficult, but adding the additional layer of timing with past selves was even more difficult. Trying to time jumps with your past selves was more frustrating than satisfying. I ended up reaching the green orb without the help of the yellow guy and then gave up on the blue orb because I couldn't get the timing right.
My recommendation is to tutorialize the player. Set the rules/expectations of the game world (what can and can't be done so the player isn't guessing if they're doing something wrong or if the game is broken). The speed and slipperiness of the characters also makes coordinating movement with past selves not fun. Perhaps the movements need to be slower and more deliberate. Lastly, I know it's a pain, but setting up different control schemes would be highly appreciated.