How to increase the performance of HTML5 game?

Question

I created a simple platformer on JavaScript.
ES6 version:

https://code.sololearn.com/WWkBJcm6X0yJ/?ref=app
ES5 version:

https://code.sololearn.com/WBGSFKX9P742/?ref=app

Do you have any idea how to increase the performance of my game?
In the cource of development, I deliberately excluded collision detections from the player's object with other game objects, as well as drawing them when they were outside the screen. I used classes, so, in contrast to my previous game, the methods of objects is on their prototype.
Nevertheless, on mobile devices, the game shows a very small FPS. While on the computer - 59 FPS.
I'm new so I could make a big mistake (error, bug) in my code. I will be glad to any help. Thanks.
P.S. There may be bugs with the buttons in the game menu. I don't know how to fix them. Positioning problem.
P.P.S Also the game goesn't work on iPad and iPhone. I don't know why.

Answer 1

I also do not expect 60 fps on mobile, I would have at least 30 fps to achieve. ... The map can expand, you can create your own levels, new game objects can be added.

Answer 2

is that whole map hard coded?

Answer 3

59 Fps is plenty, and I wouldn't expect it to be that high on a mobile device