Not bad, but its not really a game. Its more of a subjectively 'fun' chore. Even people with the best mental fortitude rage at this game. External factors like monitor size helps you win games so 'skill' is undeniably determined by unfair means to a noticeable extent. Can have fun without being competitive, but can get repetitive and boring extremely fast. If you want to have good fun after a long day, this is the worst game for it. But if you are already a hardcore gamer with a competitive setup its great for you.
Honestly, Riot just made another free, addictive-toxic game with in-game purchases concealed in glitter graphics and unrelated cinematics because LOL brings in fat profits and that's it.