I think the idea is that it's a strategy RPG given he drew parallels to how Final Fantasy was setup with Terra Battle 2 being a new mainline game, and this is a spin-off with a strategy like title a la Final Fantasy Tactics.
The full image has a lot of varying terrain height and things like bridges and rivers that would fit with a Tactics-esque game as well:
I was going to say that Terra Battle already feels like a strategy game.
When looking at the new image though, I can see how it would be a strategy RPG.
Interesting, so the quality of the game was not the reason it tanked.
I'd say the quality of the game was good. The problem was the time between content updates.
I also didn't like that the game wasn't available in most regions of the world, had to get the .apk to install it.