Nostalgia: Op.2

Nostalgia: Op.2 (Op.2 meaning the second opus) is a piano based rhythm game in Konami's BEMANI franchise. It is the second game in the Nostalgia series and a spiritual successor to Konami's Keyboardmania series.

The game consists of falling bars corresponding to certain areas of the keyboard. When the bars cross the judgement line it is time to play that key. There are three type of notes - Normal note which you play as normal, slide note where you slide your hand across the keyboard and trill note where you rapidly and alternately press two neighbouring keys.