Cookie Clicker
€4.99 at Steam. It's at full price right now; it has been as low as €1.59.
Best PC price
€4.99
All-time low
€1.59
An idle game about making cookies! Originally released in 2013 on the web, and actively developed since then. This is the official version for Steam.
CasualIndieStrategySimulationSingle-player