Not enough clarity in the game
By clarity i mean that there are many things unexplained that impact the game.
Here are some examples:
- What exactly is spell damage and what types of abilities does it work on?
- What item will these two unequiped components create?
- What is the stun duration on Lissandra?
- What is the mana burn/shield number on Kassadin?
- What are the base stats of champions?
All of these and other unmentioned ones should be available in the game.