I barely play on my iDevice these days, but here are some common logic solutions to reduce crashes
1) Make sure you're only running the one app and aren't Multitasking/Backgrounding any apps.
The iDevice has alot less ram to dedicate towards your app than say, on a computer.
2) As was mentioned before, disable image animations and sound, aswell as setting the 'font' to the simpler font (Less to render)
3) Stick closer to your access point.
The further away from your wifi access point you are the harder your iDevice has to work to keep up the connection.
4) Log out in your house or an area that is commonly quiet.
I have noticed that the most common time for the app to crash is when logging on. (Personally anyway) That is because the ipod is attempting to set up a connection with EVERY SINGLE CLIENT nearby at the same time.
Think about it, if you log into a quieter area, less connections to set up, meaning an easier job for your device.