The Red Alert is a mini-boss battle where you step on it and you have to battle the mini boss. To avoid the Red Alert, do the following step: Before beating Wizard, you beat Montgomery stage and before you go to the red alert which is in the specific way you want to enter, go to the zone that isn't affected by the Red Alert Zone and beat the Stage. After doing that, if the same stage is infected with the Red Alert, you need to go to Montgomery. After going there, press start to pause the game and select return. The Red Alert zone will change to another location. You only do that with the first Wizard and Ultron boss battles.