Performance optimization checklist for Flash Lite game / application development
Tips for optimizing ActionScript
Spread out initialization across movie and not all on Frame 1, doing to much in the first frame like slowdown the start of the application
Using gotoAndPlay() still loads content in the frames you skip, so use separate movie clips and link it via Actionscript
Garbage collection should occur every 60 seconds or on 20% memory spike, so manually remove objects and variables when they are no longer required, like clearing setIntervals, listeners etc., before removing movie clips for which it is assigned.
Variables local to functions are processed faster than global variables, so use the var keyword wherever possible.
Pre-calculate values using Math and store for access later, so try and minimize the use of Math and floating point numbers
Remove smaller loops and write each iteration separately
Use XML carefully and in small chunks, if possible, use simple name/value pairs for data. But light-weight data is good for your application and costs users less