You can play completely offline. All single player levels do not require internet access, and can run smoothly on the subway and during breaks. The progress is automatically saved locally, and restarting after shutdown will resume from the last pause. When offline, the tower will still accumulate resources, and rewards will be automatically distributed after reconnecting to the network. There are no mandatory advertisements, only short videos available for viewing on the main interface in exchange for extra life. Activate a defense anytime and anywhere, efficiently relax.