OMG :D
Thank you very much for the link to that guide
I was looking for one before placing the discussion but could not find something because I was looking for Construct 3.
I had only two sprites but they had large transparent spaces and I had no idea that this could affect performance.
point number 5 "Avoid large areas of overlap between objects" is something that I was unaware of, and it is a problem of this project that the previous one did not have.
After solving these things the performance improved a LOT.
I also repaired a bad loop that the game had, and everything is perfect, only missing maybe some tweaks but the problem is more than solved.
I will not forget to keep these things in mind for a future project.
Thank you HolidayExplanation.