If it only happens while moving the character, consider what you're doing when the character moves. Try deactivating each part and testing again until it runs smoothly.
It's hard for us to tell from an exported game instead of looking at your code, but it appears for example that you're creating a ton of sprites or particles on the ground. I don't know how powerful the device you're having difficulty with is, but if it's old enough, that effect could be what tips it above what it can handle at 60 fps.
Transparent pixels take more work to render than opaque ones. 100% transparent pixels still take work to render unless the object is invisible. Creating and destroying objects takes more work than it might seem. Text boxes take more work to render than sprite fonts, especially if you're updating them every tick instead of only when they change. Make the text box as small as possible because you don't want the GPU to waste time drawing invisible areas. Do you have your project set to clear the background? That also uses more processing power, and your background is hidden, so you can turn that off. If you're using effects on mobile, don't because they're crazy intensive.
Also, read this page. https://www.scirra.com/manual/134/performance-tips
All of these things and more can add up.