Closure compiler advanced mode - this can speed up 10-20
don’t write deep chain of inherited class, calling super methods are expensive
reuse your objects, don’t create new instance too often, not only creation is slow, Garbage Collection is slow too
some calculation don’t need to be run every frame, you can use cc.Schedule to time it, (for example, AI logic is good enough when run 4 times a second)
These are just general tip
what is the type of your game? and what platform are you targeting?