From the Super Mario Wiki
The Timer is a souvenir located in the Doodads folder in WarioWare: Twisted! It acts like a standard kitchen timer, with a maximum of five minutes for the time limit. The background also resembles a kitchen, containing boiling pots, hanging utensils, and a sink. The time is manually set by tilting the console to the desired position. Once there only remains two minutes until the alarm finishes, a pot in the background starts to visibly simmer. After the allotted time has passed, the timer loudly rings, which can be shut off by pressing . The timer can then be used once more. Manually rotating the timer to zero creates the same effect as letting it naturally reach zero.