4399 Grows Legend of Mushroom by 32.73% with Playtime

4399, one of the Chinese largest game publishers, focuses on driving success in the Japanese market for their hit title Legend of Mushroom. The team’s goal was to expand the user base in Japan and strengthen the in-game ecosystem, all while maintaining strong return on ad spend (ROAS).

Japan is a competitive UA market. Low-cost installs won’t make a difference: 4399 needs high-quality users who stay, spend, and support a healthy in-game economy. They are looking for a performance channel that could maintain a healthy ROAS at scale.

4399 partnered with adjoe and activated the Playtime ad unit: a rewarded model that drives real in-game engagement. Instead of paying for installs, adjoe paid for time. Users earned rewards by playing, not just downloading, encouraging deeper engagement and stronger retention.

To take full advantage of seasonal spikes, the team scaled budgets during Japan’s Golden Week; capturing peak traffic and maximizing return.

The results validated the model: Playtime users engaged longer, converted better, and outperformed ROAS goals. Within just one month, 4399 scaled up their spend by 46%, growing D7 ROAS on Android by 32%, marking a significant improvement in profitability over time.

Encouraged by the performance, 4399 will continue scaling with adjoe to grow Legend of Mushroom in Japan. With Playtime’s engagement-first format and a data-led approach, the team is set up for sustainable growth.

Even though initial ROAS started slower, long-term ROAS exceeded expectations, proving adjoe’s strength as a sustainable, high-quality acquisition partner.