The Soleanna Medals come in gold, silver and bronze. Gold medals are received after missions or objectives, such as accomplishing a Town Mission or finishing an Action Stage, making them this game's counterpart to the Emblems from Sonic Adventure and Sonic Heroes. Silver medals are hidden all throughout Soleanna and can be located around Town Stages and Action Stages, usually in difficult to reach or hidden places. Bronze medals are the objectives in some of the missions.
In Sonic Unleashed, there are two types of medals: Sun Medals and Moon Medals.
In the Xbox 360/PlayStation 3 version, Sun and Moon Medals can be found in hub villages, entrance stages, missions and action stages. According to Professor Pickle, collecting Sun Medals will increase Chip's Sun power level. Collecting Moon Medals will increase Chip's Moon power level. Certain power levels will allow access to Gaia Gates that lead to action stages. There are total 200 Sun Medals and 200 Moon Medals.
In the Wii/PlayStation 2 version, Sun Medals are gained by playing night stages, and Moon Medals by playing day stages - it works backwards in a nutshell. In tutorial missions, mini missions or bosses, only one medal can be obtained per mission (the boss medals are obtained by gaining S-Ranks). In normal stages, it is possible to get a maximum of three per level by getting S-Ranks. In the night levels, one medal is obtained depending on time, one depending on rings and one depending on Gaia Force points. There are total 103 Sun Medals and 71 Moon Medals.