A concept that I think could be cool. Actually, the fantasy is similar to my game, but with very different vision and in another genre. I didn't get too far, but here are some feedback that could help the project or maybe become experience for a next one.
I just played with the first mask, but I found the controls to be janky and confusing. This is how I would simplify:
Keep WASD for movement
Keep the jump working for every character and don't override this action. You can make the jump different for each character then. For example, the monkey jump can be shorter, but if it touches any rope, make it snap to it automatically.
LMB for the mask hability (Add then a HUD showing what the LBM does contextually. When I get near the box, show me "carry", and then show me "throw")
RMB hold to show the mask change wheel, then release to transform
I have no idea if this framework would work for the other masks, but I think it could be a limitation that would make it more intuitive and simple. This way, you keep movement and jump on left hand. Global actions that always work and won't surprise the player. And then mask related actions on the right hand, change the mask the and the mask specific ability.
The second annoying part were the gameplay mechanics and level design. I had no idea I had to collect the key. And throwing the box into the key did not make sense. And after collecting the key, nothing changed in the world to indicate that I had to go to the right platform to clear the level somehow. These mechanics and state need to be better communicated for the player.
As I said, i played for a really short period, so you can take with a grain of salt. But felt like I should give this sincere feedback that could help this or future projects! Good luck!