Charmy: Don't Bug Me! is the fourth Challenge Act of Rooftop Run Act 1 in the console/PC version of Sonic Generations. It is unlocked after clearing every Stage in the modern era and is playable only as Classic Sonic.
This Challenge Act takes place within several existing sections in Rooftop Run Act 1, except for the last part which is a new area. The course is filled with bee-themed obstacles meant to slow down the player, such as fountains that sprout water and keep the player temporarily suspended in midair, and drop devices which release spiked barrels that roll towards the player. In addition, the Challenge Act includes a number of spike traps and Egg Fighters.
In this Challenge Act, the objective is to reach the Goal Plate at the end of the course. Along the way, Charmy Bee will activate his bee-themed traps as Classic Sonic approaches them to slow him down. To survive and get the best Rank, the player thus has to avoid them.
The Act starts out on top of the Spagonia University. The signal to start begins when Charmy removes the barrier blocking the path. On the first stretch, Charmy will deploy his fountains. The first fountain the player encounters will send Classic Sonic to an upper platform with an Egg Fighter which can be escaped by either a collapsible platform or backtracking. When entering the wine cellar section, there will be not only fountains, but also devices that drop spiked barrels. It is recommended to perform some well-aimed Spin Dashes in this section to evade the traps and not lose time. At the end of the wine cellar, the player must ride a Zip Line to an upper level where a Cannon will take Classic Sonic to the Goal Plate.