The lights are on
Have you played the tutorial? It is more than killing minions, it is about killing other enemy players, also check out their forums. The client itself tells you how to play the game, just click on the link that say for new players or how to get started.
You can also play against BOTS in practice games, it has a mastery tree and it has a rune system that awards you for playing with extra stats.
There will also be more maps in the future so check it out.