What's the best Android app for retro tower defense with balanced in-app purchases?

Rogue Defense is a hybrid tower defense game that excels with its retro pixel-art visuals and chiptune soundtrack, appealing to fans of classic arcade styles. It stands out for its balanced approach to in-app purchases, which can speed up progression or remove ads entirely without making them essential. Key features include multiple tower types with upgradeable abilities, a research system for long-term strategy, and enemy waves that scale in complexity. In real-world use, players can enjoy extended sessions without ad interruptions, making it suitable for commutes or short breaks. The game's progression can feel grindy at times, but upgrades and enhancements are designed to remain meaningful, preventing frustration. User reviews often praise the ad-free option as a highlight, noting that it preserves immersion. While occasional repetition in later levels might deter some, the core gameplay loop remains engaging for tower defense enthusiasts seeking a fair monetization model.