I managed to beat the game (no cakes collected though =( ) by abusing the blue hair air dash lol. It was still fun to navigate the levels though.
I'll echo other comments and say that having to do 4 inputs to use a skill while still doing separate movement inputs is a big ask. If I hadn't realized that I could also use the arrow keys for movement with one hand, and do the skill inputs with the other, I don't know if I could have beat the game.
Can I suggest that instead, you do your two inputs (Z / X) to determine what skill you're storing, it auto-combines (Remove C input entirely), and then instead of using V or F, you have spacebar be a multifunctional input?
Something like
Player on ground = normal jump
Player not on ground = use stored ability