I stumbled upon this project and found the premise to be very interesting, so I downloaded the game and gave it a whirl.
The visuals are really nice, and I was impressed with the frame count and smoothness of all the character animations. The controls are definitely a little bit complicated and take some time to get used to, but they still handle well enough.
I feel like the game's mechanics are in an awkward spot in this current state, though. The waiting period between swapping characters feels like it simultaneously takes too long and is too accessible. I didn't have any success with swapping between characters in the middle of combat and instead found that poking the regular enemies with Sword two times before running away was the most effective strategy. For the boss, I simply used Shield's dodge to get behind it and summoned Sword with the shift key to get some damage in from a safe distance; the energy bar regenerates quickly enough that I can just switch to Sword and run away before I can switch back to Shield. These strategies felt kind of like exploits and seemed to undermine the main idea of switching between characters on the fly.
Overall, I would consider this project to have a really promising concept that is in need of some additional balancing and polishing work alongside more content. Well done!