Hi,
I am not familiar with slot machines, therefore some general remarks.
1. It is not nice to see only the bet spinner drop down list at startup. I think it is better to wait until the user wants to change it.
2. Close the playtable screen by using close screen, otherwise you may fill up memory.
3. Make some procedures! For example the event handling for sprite_spin1 touched and sprite_spin2 is almost the same. The differences you could provide as input to a procedure that is called from both sprite events.
4, The sounds did not play initially. After a few tries, the sound could be heard. I do not know why.
5. Why do the two sprites have the same picture? In this way it makes no difference which one is on top.
6. A nice touch would be some graphics for the buttons.
Cheers, Ghica.