Hey, hello again! I am overwhelmed in the best way by this new analysis (hehe). I sincerely appreciate the time and effort dedicated!
Desing issues. Indeed, there are design issues that were sacrificed due to the restricted time for the game development. The addition of keys images in the tutorial or the justification of texts, even dosing the information so as not to overload... They are all excellent ideas!
Motors. Regarding the rest... I don't come from the world of programming or videogame development. I'm learning to get out of my comfort zone while doing things I like, but coding has always been a problem. Tools like Bitsy, GDevelop, Twine, RPGMaker... (I'll also try Gb Studio, but I have an eternal lack of time due my work, hehe; I love the idea of restrictions to force creative solutions) help people like me a lot. We won't do the most polished things, but it serves to democratize creativity and expand gaming ideas.
Screen. Finally, I already solved the screen failure, thanks to your advice. Now you should be able to play it on GdGames without any problem (https://gd.games/kolde/smash-rush). When I make some more minor changes and design corrections, I will also update the version on itch.io.
Again, I don't know how to thank you for your time, it's quite an honor!! ^^