Advance Wars 2 is a game of calculated risks, but sometimes the RNG (Random Number Generation) regarding critical hits or weather can ruin a perfect run. Because the game saves automatically after a mission ends, but allows you to save during a mission, players can utilize the "Save Scum" technique.
Eagle and Drake are your allies (AI controlled), but they are incompetent. You face Lash with superior firepower. Solution: Use Eagle yourself. His Lightning Strike CO Power can break the AI’s economy quickly. Focus on destroying the enemy's bases, not their units. If you let Lash keep a single base, she will spam Megatanks.
A: Double check your Hard Campaign list. You may have missed a hidden mission. Some missions on Hard Mode are only unlocked by achieving certain speeds on previous missions. Go back and ensure all 24 slots on the Hard Campaign map screen have gold A-rank medals.
Reduces unit costs to 50% of their original price.