Hold down L+R+Y+Down for 3 seconds to enable cheats, then press:
When using a ranged unit you can fire and then slightly push the move stick in a direction and then press attack again to hit them another time, but a lot faster. Note: this will not work for the mortar or melee units.
Use the Stormbringers, get ten Ice Mages, then get the full health and weapon upgrade. The Ice Mages are now almost unlimited (take a long time to die). This works best in multi-player mode.
JimBob13666.