Highly addictive game and not in a good way. Prepare to be robbed of a lot time (and money if you want to have any chance of advancing past basic levels). What you get in return is a buggy game, clearly designed to hack your brains dopamine/reward system. Some peculiar game behaviour includes being matched against very skilled players, as soon as you approach significant milestones. This usually knocks you back at least one level. In-game rewards are just enough to make you spend $ in the shop.