Complete every daily challenge. These often provide the premium currency needed for permanent stat boosts that stay with you through every round.
If the game offers "Double Gold" or "Free Chests" for watching short clips, take them. It’s the fastest way to bridge the gap between levels without spending real money.
Finding a reliable "hack" or "mod APK" for can be tricky and often risky. Most sites claiming to offer unlimited money or unlocked features are unreliable and may contain malware.