How to set up phone controls?
Create sprites that you use as buttons and use the touch plugin and the "simulate control" actions.
Is it hard to test? (I have an Android Samsung S8 and friends with iPhones)
Preview is easy on both, but when it comes to the actual installing for testing, Android is far easier.
2. Game type platformer
Generally all you´ve listed is possible but I recommend starting with smaller goals, then adding on top later.
suggestions?
Devour the documentation. If you´re stuck somewhere, check the documentation first. Most likely you´ll find your answer there. :)