So my game used to have a very poor performance while previewing on a mobile device, but I have made some 'radical changes' (like making images way smaller, making events more efficient, followed this https://www.scirra.com/manual/134/performance-tips) and it had a nice result. But it is still not enough.
The objects using CustomMovement sometimes move in a slow-motion. My min FPS is 30, but the FPS never drops below 30 when moving (the fps drops when the object is triggered to move).
I have also no effects, no objects that move all the time, no animations that keep replaying (i have a maximum of 15 objects that have looping animations, and these objects are very small), no fading objects.
Also, there is this problem with the screen which keeps blinking even though i have 'Clear Background' set to 'No'.
I have over 300-400 objects in each level, and over 900 collision checks per sec.
I have tried cutting the number of objects on half, but that didn't change anything (90% of my objects are not moving at all), the CustomMovement and some objects I am being scrolling (even though I use 'dt') are still in slow-motion and the screen keeps blinking.
So, this is my first project and I am not very experienced with making performance more efficient....