I'll study the video deeply, thank you.
I think I need to study more on game designing.
I'll share my new idea and progresses with you shortly.
Dear ootc, after thinking about it, I decided to try the "easier" route first (at least for the moment), making the enemies bad. I have reduced the enemy size (they seemed a little too big to me) and added more checkpoints to make the game easier. I am also working on a new look for the hero, and I plan to profoundly restructure all the levels (I want them to be very varied and, above all, very fun). I attach a screenshot where you can see the new enemies (the new look of the hero is not yet final). What do you say?