Too difficult for me to play, I can't fully understand the tactics.

The game icon caught my attention quickly. My curiosity led me to play this game, but it turns out that it's another auto-battling game that got me bored. I have been playing it for 30 minutes now, but I still don't know what the goal is. It doesn't have tutorials or even a map. The instructions are confusing too. It has good graphics and character, but the gameplay is difficult for me.