In this language, the CPU will only ever run one command at a time, going down the line in the order you wrote them. If it seems like the system is doing several things at once, it's because the program was organized so that it would do a little bit of everything for every frame of animation.
Here's an example of how I structure my programs:
Set initial conditions -- draw the screen, set variables, etc.
Do this forever:
Check inputs -- buttons, touchscreen, whatever I'm using
Change data based on inputs
Calculate new positions for onscreen objects based on data -- how far does everything move in 1/60th of a second?
Move onscreen objects to their new positions
Repeat.
You also have to check for special events that change the state of your program - if the player goes through a door or finishes a stage or is defeated by an enemy, etc. and move to different loops throughout your program accordingly.
As far as breaking out of a loop, yes, you can do it if you need to, but how you do it depends on the kind of loop you've got.
If it's:
@LOOP
GOTO @LOOP
breaking out is as simple as GOTO @SOMEWHERE. But if you're using a looping command (WHILE, REPEAT, FOR) you should use the BREAK command to end your loop and free up the memory that the system uses while running those kinds of loops.
