I played Swarm Simulator on iphone for a good while, it's a pretty compelling idle game.
I'd say my main issue with idle games is how much they reward you for active play. In Cookie Clicker's case, at random, golden cookies will appear that when clicked apply a random boost, e.g. a 7x multiplier. Eventually you unlock upgrades so that another one may appear while the boost is active, leading to a double boost. The ultimate combination involves a multiplier, a boost to cookies per click (again active), then selling a lot of buildings for an additional short-lived bonus, then clicking like mad.
You can earn a year's worth of idling / not playing within a minute then. If it's not more.
I'd say my main issue with idle games is how much they reward you for active play. In Cookie Clicker's case, at random, golden cookies will appear that when clicked apply a random boost, e.g. a 7x multiplier. Eventually you unlock upgrades so that another one may appear while the boost is active, leading to a double boost. The ultimate combination involves a multiplier, a boost to cookies per click (again active), then selling a lot of buildings for an additional short-lived bonus, then clicking like mad.
You can earn a year's worth of idling / not playing within a minute then. If it's not more.