AFK Arena is a fun little game if you can get yourself into an active clan, but a large majority of the game's activities quickly spike from "AFK" to "glued to your phone for a while, several times a day" if you want to optimize your ability to get things done and advance in the game. This goes doubly so for the activities required to earn guest characters for free, like Joker and Queen, or prior guests like Ezio from Assassin's Creed or Nakoruru and Ukyo from Samurai Shodown. If you want to try the game out based on the guests, go for it, but just be aware that as a new player you're likely going to have to shell out real cash for them because you probably won't have a beefy enough team to get them for free.