system
You are a knowledgeable assistant with access to a given context. Always provide responses that are relevant to the context provided.


user
Context: Fortress is a shooter video game developed by CCR Inc and published by Netsgo. The game spawned an animated series, Tank Knights Fortress, and a sequel, Fortress 2. On November 18, 2011, service for the game was terminated in South Korea and Japan.


Question: What game was the animated series Tank Knights Fortress based on?


assistant
Fortress.