The character swapping in this game is annoying, unlike other metroidvania games like Astalon or Monster Boy and the cursed kingdom.
Why? Because one character can jump and the other cannot, but it's worse than that. You use the same button for jump on one of them as you do for dashing on the other one. My brain keeps telling me to press it to jump when I'm the other guy. It's entirely manageable, but not a fun mental excersize to engage in and it makes playing the game unpleasant to me. It slows the gameplay down as you keep telling yourself 'oh no, wait, I can't do that, gotta press the character swap button'. It acts as a needlessly annoying interference.
I don't see what purpose it serves to break up the age-old 'your character can run & jump & dash' into 2 separate beings. It just adds a layer of clunk to a basic QoL one is used too as a means of creating some challenge here and there. With that line of thinking, why don't we make it take 6 well-memorised button presses like its a Mortal Kombat combo in order to do something as basic as jump.