This anime is a spin-off? I can't say it like that tho because at the end they reveal its all just imagination, same like in the anime. One thing for sure is that this anime is a fan service for Mecha genre fans out there. And I'm not one of them. So when i watch all the short 7 episodes, its feel like a chore. Every episode is 3 minutes long on average, so you can finish this anime in one sitting. What is really love is the ending. I'm not embarrassed to say that i am almost crying at the end there. Not onlybecause the Mecha story, but also because Rikka relationship with Yuuta.

Art is obviously very very great. The fighting animation and the robot all looks well made. They use the same artstyle as the main anime. I can't compare the animation to other Mecha anime because i never watch one. But i think i can safely say that this is beautiful. The apocalyptic city in the background really fit the whole vibe this fight bring. At first I'm not really enjoying it because its just filled with action. But near the end is one of the most beautiful story i ever watch.